Nitratireductor shengliensis sp. nov., Isolated from an Oil-Polluted Saline Soil

Two Gram-negative, non-motile, short-rod-shaped bacterial isolates, designated 110399^T and 110248, were isolated from an oil-polluted saline soil in Shengli Oilfield, Eastern China. The two strains shared 99.9 % 16S rRNA gene sequence similarity with the DNA–DNA relatedness value being 80.0 %. They were both capable to grow at 20–40 °C, pH 7–9, and 1–9 % (w/v) NaCl with the optimum growth happened at 30 °C, pH 8, and 2–6 % (w/v) NaCl. The phylogenetic analysis based on 16S rRNA gene sequences revealed that the two strains were members of Nitratireductor and most closely related to Nitratireductor pacificus pht-3B^T and N. basaltis J3^T with the 16S rRNA gene sequence similarities being 97.1 and 97.0 %. The DNA–DNA relatedness between the novel strains and two type strains were below 27 ± 7 %. The strains 110399^T and 110248 also differed from N. pacificus and N. basaltis in nitrate reduction, salt tolerance, enzyme activities, and utilization of carbon sources. The major cellular fatty acids of strain 110399^T were C_19:0ω8c cyclo (10.5 %) and Summed Feature 8 (C_18:1ω7c and/or C_18:1ω6c, 41.5 %) which are typical in the genus Nitratireductor. The predominant ubiquinone was Q-10. The genome DNA G+C content of strain 110399^T and 110248 was 61.1 and 61.7 mol%. On the basis of genetic, phenotypic, and chemotaxonomic analyses, strains 110399^T and 110248 represent a novel species within the genus Nitratireductor, for which the name Nitratireductor shengliensis sp. nov. is proposed. The type strain is 110399^T (=CGMCC 1.12519^T = LMG 27405^T).     

Thalassobius aquaeponti sp. nov., an alphaproteobacterium isolated from seawater

A Gram-stain-negative, aerobic, non-motile and rod-shaped or ovoid bacterial strain, GJSW-22^T, which was isolated from seawater at Geoje island in South Korea, was characterized taxonomically. Strain GJSW-22^T was observed to grow optimally at 30 °C, at pH 7.0–8.0 and in the presence of 2.0 % (w/v) NaCl. In the neighbour-joining phylogenetic tree based on 16S rRNA gene sequences, strain GJSW-22^T grouped with the type strains of Thalassobius species, forming a stable cluster with the type strain of Thalassobius aestuarii (bootstrap value of 83.2 %). Strain GJSW-22^T exhibited the highest 16S rRNA gene sequence similarity value (98.0 %) to the type strain of T. aestuarii. It exhibited 16S rRNA gene sequence similarity values of 95.6–96.1 % to the type strains of the other Thalassobius species. Strain GJSW-22^T was found to contain Q-10 as the predominant ubiquinone and C_18:1 ω7c and 11-methyl C_18:1 ω7c as the major fatty acids. The major polar lipids of strain GJSW-22^T were identified as phosphatidylcholine, phosphatidylglycerol, phosphatidylethanolamine, one unidentified aminolipid and one unidentified lipid. The DNA G + C content of strain GJSW-22^T is 60.3 mol % and its mean DNA–DNA relatedness value with the type strain of T. aestuarii was 23 %. Differential phenotypic properties, together with the phylogenetic and chemotaxonomic data, confirmed that strain GJSW-22^T is distinct from other Thalassobius species. On the basis of the data presented, strain GJSW-22^T is considered to represent a novel species of the genus Thalassobius, for which the name Thalassobius aquaeponti sp. nov. is proposed. The type strain is GJSW-22^T (=KCTC 42115^T = NBRC 110378^T).     

Siansivirga jejunensis sp. nov., isolated from seawater of Jeju Island in Korea and emendation of the genus Siansivirga

A Gram-stain negative, non-flagellated, non-gliding and rod-shaped bacterium, strain JHH-2^T, was isolated from seawater collected in Jeju Island, Korea. The novel isolate was found to grow at 25–30 °C, at pH 6.5–7.0 and in the presence of 1–2 % (w/v) NaCl. Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain JHH-2^T is closely related to Siansivirga zeaxanthinifaciens JCM 17682^T, with 16S rRNA gene sequence similarity of 96.6 %. The predominant respiratory quinone was identified as menaquinone-6 and the major cellular fatty acids were detected as iso-C_15:0, C_16:0 and iso-C_17:0 3-OH. Polar lipid profiling revealed the presence of phosphatidylethanolamine, an unidentified glycolipid, four unidentified aminolipids and two unidentified lipids. The DNA G+C content of the chromosomal DNA of the type strain is 35.6 mol%. On the basis of several distinct phenotypic characteristics and phylogenetic analysis, a new species of the genus Siansivirga, Siansivirga jejunensis JHH-2^T sp. nov. is proposed. The type strain is JHH-2^T (= KCCM 92030^T = JCM 19228^T).     

Cohnella humi sp. nov., Isolated from Russian Soil

A Gram-positive, catalase and oxidase positive, rod-shaped bacteria, and spore-forming, designated as J20-3^T was isolated from a peat soil, collected near a coal mine at Prokopyevsk, (GPS; N53°52′51″, E86°43′39″) Kemerovo Oblast, Russia. A polyphasic taxonomy study using phenotypic, phylogenetic, and genotypic method was performed to characterize strain J20-3^T. Comparative 16S rRNA gene sequence analysis indicated that strain J20-3^T represented a novel subline within the genus Cohnella in the family Paenibacillaceae. According to 16S rRNA gene sequence, strain J20-3^T showed 93.7–97.2 % similarity levels with other Cohnella species. Strain J20-3^T exhibited relatively low level of DNA–DNA hybridization value with type strains KACC 11643^T (40 %), KACC 11771^T (37.5 %), and KACC 15372^T (30.5 %). The strain showed typical chemotaxonomic characteristic of the genus Cohnella, with the presence of predominant respiratory quinone MK-7; major fatty acids are C_15:0, C_16:0, iso, and C_16:0. The DNA G+C content of the strain J20-3^T was 56.3 mol%. The polar lipid profile of the strain J20-3^T included major amount of diphosphatidylglycerol, phosphatidylglycerol, and phosphoatidylethanolamine. On the basis of its phenotypic and genotypic properties, and its phylogenetic distinctiveness, strain J20-3^T should be classified as a novel species in the genus Cohnella, for which the name Cohnella humi sp. nov. is proposed.     

Litoribrevibacter albus gen. nov. sp. nov., isolated from coastal seawater,Fujian province,China

A Gram-stain negative, short rod-shaped aerobic bacterium with flagella, designated strain Y32^T, was isolated from coastal seawater in Xiamen, Fujian Province of China. 16S rRNA gene sequence comparisons showed that strain Y32^T is a member of the family Oceanospirillaceae, forming a distinct lineage with species of the genus Litoribacillus. The 16S rRNA gene sequence similarities between strain Y32^T and other strains were all less than 94.0 %. Strain Y32^T was found to grow optimally at 28 °C, at pH 7.0–8.0 and in the presence of 4–5 % (w/v) NaCl. The major fatty acids were identified as Summed Feature 3 (comprising C_16:1 ω7c and/or C_16:1 ω6c, 49.4 %), C_16:0 (17.7 %), C_14:0 (6.9 %) and C_18:1 ω9c (5.4 %). The major respiratory quinone was identified as ubiquinone-8 (Q-8). The major polar lipids were identified as diphosphatidylglycerol, phosphatidylethanolamine and phosphatidylglycerol. The DNA G+C content of strain Y32^T was determined to be 55.6 mol%. According to its morphology, physiology, fatty acid composition, polar lipids composition and 16S rRNA gene sequence data, strain Y32^T represents a novel species of a new genus in the family Oceanospirillaceae, for which the name Litoribrevibacter albus gen. nov. sp. nov. is proposed. The type strain of Litoribrevibacter albus is Y32^T (=MCCC 1F01211^T=NBRC 110071^T).     

Acinetobacter apis sp. nov., isolated from the intestinal tract of a honey bee,Apis mellifera

A novel Gram-negative, obligate aerobic, non-motile, and both coccobacillus- and bacillus-shaped bacterium, designated strain HYN18^T, was isolated from the intestinal tract of a honey bee (Apis mellifera). The isolate was oxidasenegative and catalase-positive. Strain HYN18^T showed optimum growth at 25°C, pH 6–7, and in the presence of 1% (w/v) NaCl in trypticase soy broth medium. The isolate was negative for hydrolyses of starch, casein, gelatin and urea, indole production from tryptone and hemolysis on sheep blood agar. A phylogenetic analysis based on the 16S rRNA gene and rpoB gene sequence showed that strain HYN18^T was most closely related to Acinetobacter nectaris SAP 763.2^T and A. boissieri SAP 284.1^T with 98.3% and 98.1% similarity (16S rRNA gene), respectively, and 84.4% similarity with Acinetobacter nectaris SAP 763.2^T (rpoB gene). The major cellular fatty acids were summed features 3 (comprising C_16:1ω7c /C_16:1ω6c ), C_12:0 and C_16:0. The main isoprenoid quinone was ubiquinone-9 (Q-9). The polar lipids of strain HYN18^T were phosphatidylethanolamine, three unidentified lipids, an unidentified phospholipid and an unidentified glycolipid. The DNA G+C content was 40.6 mol%. DNADNA hybridization experiments indicated less than 33 ± 10% relatedness to the closest phylogenetic species, Acinetobacter nectaris SAP 763.2^T. Thus, the phenotypic, phylogenetic and genotypic analyses indicate that strain HYN18^T is a novel species within the genus Acinetobacter, for which the name Acinetobacter apis is proposed. The type strain is HYN18^T (=KACC 16906^T =JCM 18575^T).     

Motiliproteus sediminis gen. nov., sp. nov., isolated from coastal sediment

A novel Gram-stain-negative, rod-to-spiral-shaped, oxidase- and catalase- positive and facultatively aerobic bacterium, designated HS6^T, was isolated from marine sediment of Yellow Sea, China. It can reduce nitrate to nitrite and grow well in marine broth 2216 (MB, Hope Biol-Technology Co., Ltd) with an optimal temperature for growth of 30–33 °C (range 12–45 °C) and in the presence of 2–3 % (w/v) NaCl (range 0.5–7 %, w/v). The pH range for growth was pH 6.2–9.0, with an optimum at 6.5–7.0. Phylogenetic analysis based on 16S rRNA gene sequences demonstrated that the novel isolate was 93.3 % similar to the type strain of Neptunomonas antarctica, 93.2 % to Neptunomonas japonicum and 93.1 % to Marinobacterium rhizophilum, the closest cultivated relatives. The polar lipid profile of the novel strain consisted of phosphatidylethanolamine, phosphatidylglycerol and some other unknown lipids. Major cellular fatty acids were summed feature 3 (C_16:1 ω7c/iso-C_15:0 2-OH), C_18:1 ω7c and C_16:0 and the main respiratory quinone was Q-8. The DNA G+C content of strain HS6^T was 61.2 mol %. Based on the phylogenetic, physiological and biochemical characteristics, strain HS6^T represents a novel genus and species and the name Motiliproteus sediminis gen. nov., sp. nov., is proposed. The type strain is HS6^T (=ATCC BAA-2613^T=CICC 10858^T).     

Paracoccus pacificus sp. nov., isolated from the Western Pacific Ocean

A Gram-stain negative, short rod-shaped, non-motile, catalase- and oxidase-positive, aerobic bacterium, designated F14^T, was isolated from the Western Pacific Ocean. Phylogenetic and phenotypic properties of the organism supported that it belongs to the genus Paracoccus. The levels of 16S rRNA gene sequences similarity between strain F14^T and other type strains of recognized members of the genus Paracoccus were 93.6–96.5 %. Growth of strain F14^T was observed at 4–40 °C (optimum, 28–30 °C), pH 6.0–10.0 (optimum, pH 7.0–8.0) and in the presence of 0–7 % (w/v) NaCl (optimum, 1–2 %). The major cellular fatty acid was summed feature 8 (C_18:1 ω6c and/or C_18:1 ω7c). The major respiratory quinone was ubiquinone-10. The polar lipid pattern indicated the presence of diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol, phosphatidylcholine and three unknown lipids. The DNA G+C content was 61.4 mol%. On the basis of polyphasic characterization, strain F14^T represents a novel species, for which the name Paracoccus pacificus sp. nov. is proposed. The type strain is F14^T (=CGMCC 1.12755^T=LMG 28106^T=MCCC 1A09947^T).     

Bizionia psychrotolerans sp. nov., a psychrophilic bacterium isolated from the intestine of a sea cucumber (Apostichopus japonicus)

A novel Gram-negative, non-flagellated, non-gliding, rod-shaped bacterial strain, designated PB-M7^T, was isolated from the intestine of a sea cucumber collected from Pohang, South Korea. Growth was observed at 4–30 °C (optimum, 25 °C), pH 6.0–9.0 (optimum, pH 7.0–8.0), and with 2.0–6.0 % (w/v) NaCl (optimum, 2.0 %). In a phylogenetic analysis based on 16S rRNA gene sequences, strain PB-M7^T was found to belong to the genus Bizionia and to be most closely related to Bizionia echini KMM 6177^T (99.0 % 16S rRNA gene sequence similarity), Bizionia hallyeonensis T-y7^T (97.9 %), Bizionia algoritergicola APA-1^T (97.5 %), Bizionia argentinensis JUB59^T (97.5 %) and Bizionia myxarmorum ADA-4^T (97.1 %). The predominant fatty acids of strain PB-M7^T were identified as iso-C_15:0 (22.2 %), iso-C_15:1 G (10.8 %), iso-C_17:0 3-OH (16.7 %) and summed feature 3 (C_16:1 ω7c and/or C_16:1 ω6c; 11.2 %). The major respiratory quinone was identified as menaquinone-6 (MK-6). The polar lipid profile of strain PB-M7^T was found to contain phosphatidylethanolamine, an unidentified phospholipid, three unidentified aminolipids and three unidentified lipids. The DNA G + C content of strain PB-M7^T was determined to be 33.4 mol% and the mean DNA–DNA relatedness values with the type strains of B. echini, B. hallyeonensis, B. algoritergicola, B. argentinensis, and B. myxarmorum were 52.9, 48.5, 46.5, 37.1 and 26.6 %, respectively. Based on the data presented, strain PB-M7^T represents a novel species of the genus Bizionia, for which the name Bizionia psychrotolerans sp. nov. is proposed. The type strain of B. psychrotolerans is PB-M7^T (= KCCM 43042 ^T = JCM 19924 ^T).     

Vibrio madracius sp. nov. Isolated from Madracis decactis (Scleractinia) in St Peter & St Paul Archipelago,Mid-Atlantic Ridge,Brazil

Three novel isolates (A-354^T, A-328, and A-384) were retrieved from apparently healthy scleractinian Madracis decactis in the remote St Peter & St Paul Archipelago, Mid-Atlantic Ridge, Brazil. The novel isolates formed a distinct lineage based on the phylogenetic reconstruction using the 16S rRNA and pyrH gene sequences. They fell into the Mediterranei clade and their closest phylogenetic neighbour was V. mediterranei species, sharing upto 98.1 % 16S rRNA gene sequence similarity. Genomic analysis including in silico DDH, MLSA, AAI and genomic signature distinguished A-354^T from V. mediterranei LMG 19703 (=AK1) with values of 33.3, 94.2, 92 %, and 11.3, respectively. Phenotypically, the novel isolates can be differentiated from V. mediterranei based on the four following features. They do not grow at 8 % NaCl; use d-gluconic acid but not l-galactonic acid lactone as carbon source; and do not have the fatty acid C_18:0. Differentiation from both the other Mediterranei clade species (V. maritimus and V. variabilis) is supported by fifteen features. The novel species show lysine decarboxylase and tryptophan deaminase, but not gelatinase and arginine dihydrolase activity; produce acetoin; use α-d-lactose, N-acetyl-d-galactosamine, myo-Inositol, d-gluconic acid, and β-hydroxy-d,l-butyric acid; and present the fatty acids C_14:0 iso, C_15:0 anteiso, C_16:0 iso, C_17:0 anteiso, and C_17:1x8c . Whole-cell protein profiles, based on MALDI-TOF, showed that the isolates are not clonal and also distinguished them from the closes phylogenetic neighbors. The name Vibrio madracius sp. nov. is proposed to encompass these novel isolates. The G+C content of the type strain A-354^T (=LMG 28124^T=CBAS 482^T) is 44.5 mol%.     

Bacillus thermophilum sp. nov., isolated from a microbial fuel cell

A novel thermophilic, Gram-staining positive bacterium, designated DX-2^T, was isolated from the anode biofilm of a microbial fuel cell. Cells of the strain were oxidase positive, catalase positive, facultative anaerobic, motile rods. The isolate grew at 30–60 °C (optimum 50 °C) and pH 5–9 (optimum pH 8–8.5). The pairwise 16S rRNA gene sequence similarities showed that strain DX-2^T was most closely related to Bacillus fumarioli LMG 17489^T (96.2 %), B. firmus JCM 2512^T (96.0 %) and B. foraminis DSM 19613^T (95.7 %). Phylogenetic analysis based on 16S rRNA gene sequences showed that strain DX-2^T formed a cluster with B. smithii (95.5 %) and B. infernus (94.9 %). The genomic G+C content of DX-2^T was 43.7 mol%. The predominant respiratory quinone was MK-7. The polar lipids consisted of diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine and unknown phospholipids. The major cellular fatty acid was iso-C_16:0. Based on its phenotypic characteristics, chemotaxonomic features, and results of phylogenetic analysis, the strain was identified to represent a distinct novel species in the genus Bacillus, and the name proposed is B. thermophilum sp. nov. The type strain is DX-2^T (=CCTCC AB2012194^T = KCTC 33128^T).     

Luteimonas dalianensis sp. nov., an obligate marine bacterium isolated from seawater

A marine bacterial strain, designated OB44-3^T, was isolated from a crude oil-contaminated seawater sample collected near Dalian Bay, China. Cells of strain OB44-3^T were Gramnegative, aerobic, rod-shaped, and oxidase- and catalasepositive. The major fatty acids were branched-chain saturated iso-C_15:0 (27.9%) and unsaturated iso-C_17:1 ω9c (14.8%). The DNA G+C content was 64.6 mol%. Phylogenetic analysis based on the 16S rRNA gene sequence indicated that strain OB44-3^T was a member of the genus Luteimonas (95–96% 16S rRNA gene sequence similarity); its closest neighbors were the type strains of Luteimonas terricola (96% sequence similarity), Luteimonas mephitis (96%), and Luteimonas lutimaris (96%). On the basis of phenotypic, chemotaxonomic, and phylogenetic distinctiveness, strain OB44-3^T was considered to represent a novel species of the genus Luteimonas. The name Luteimonas dalianensis sp. nov. is proposed, with strain OB44-3^T (=CGMCC 1.12191^T =JCM 18136^T) as the type strain.     

Mariniflexile ostreae sp. nov., a member of the family Flavobacteriaceae isolated from an oyster

A Gram-negative, aerobic, non-flagellated and rod-shaped bacterial strain able to move by gliding, designated TYO-10^T, was isolated from an oyster collected at Tongyoung on the South Sea, South Korea. Strain TYO-10^T was found to grow optimally at 30 °C, at pH 7.0–8.0 and in the presence of 2.0 % (w/v) NaCl. Phylogenetic trees based on 16S rRNA gene sequences revealed that strain TYO-10^T joined the cluster comprising the type strains of Mariniflexile species. Strain TYO-10^T exhibited 16S rRNA gene sequence similarity values of 95.4–95.7 % to the type strains of Mariniflexile species and of less than 95.4 % to the type strains of other recognized species. Strain TYO-10^T was found to contain MK-6 as the predominant menaquinone and iso-C_15:0, iso-C_15:1 G, anteiso-C_15:0, iso-C_17:0 3-OH and iso-C_15:0 3-OH as the major fatty acids. The major polar lipids of strain TYO-10^T were identified as phosphatidylethanolamine and an unidentified lipid, which is similar to those of the type strains of Mariniflexile species, but different from those of other phylogenetically related species. The DNA G+C content of strain TYO-10^T was determined to be 35.9 mol%. The differential phenotypic properties, together with the phylogenetic distinctiveness, revealed that strain TYO-10^T is separated from other Mariniflexile species. On the basis of the data presented, strain TYO-10^T is considered to represent a novel species of the genus Mariniflexile, for which the name Mariniflexile ostreae sp. nov. is proposed. The type strain is TYO-10^T (= KCTC 42113^T = CECT 8622^T).     

Loktanella aestuariicola sp. nov., an alphaproteobacterium isolated from a tidal flat

A Gram-stain negative, aerobic, non-motile and coccoid, ovoid or rod-shaped bacterial strain, J-TF4^T, which was isolated from a tidal flat in the South Sea of South Korea, was characterized taxonomically. Strain J-TF4^T was found to grow optimally at 30 °C, at pH 7.0–8.0 and in presence of 2.0–3.0 % (w/v) NaCl. In the neighbour-joining phylogenetic tree based on 16S rRNA gene sequences, strain J-TF4^T fell within the clade comprising the type strains of Loktanella species, clustering with the type strains of Loktanella cinnabarina, Loktanella hongkongensis, Loktanella soesokkakensis, Loktanella pyoseonensis and ‘Loktanella variabilis’ showing sequence similarity values of 97.2–98.4 %. The strain exhibited 16S rRNA gene sequence similarity values of 94.1–95.4 % to the type strains of the other Loktanella species. Strain J-TF4^T was found to have Q-10 as the predominant ubiquinone and C_18:1 ω7c as the major fatty acid. The major polar lipids of strain J-TF4^T were identified as phosphatidylcholine, phosphatidylglycerol, diphosphatidylglycerol, an unidentified glycolipid and an unidentified aminolipid. The DNA G+C content of strain J-TF4^T was determined to be 67.9 mol% and its mean DNA–DNA relatedness values with the type strains of five phylogenetically related Loktanella species were 17.7–23.3 %. Differential phenotypic properties, together with the phylogenetic and genetic data, demonstrate that strain J-TF4^T is separated from other Loktanella species. On the basis of the data presented, strain J-TF4^T is considered to represent a novel species of the genus Loktanella, for which the name Loktanella aestuariicola sp. nov. is proposed. The type strain is J-TF4^T (=KCTC 42135^T=NBRC 110408^T).     

Gordonibacter faecihominis sp. nov., isolated from human faeces

A novel actinobacterial strain, designated CAT-2^T, was isolated from human faeces as a bacterium capable of dehydroxylating (+)-catechin derivatives. Strain CAT-2^T was found to be strictly anaerobic, Gram-positive, non-motile and non-spore-forming coccobacilli. The major fatty acids were identified as C_16:0 DMA (dimethy acetal), C_16:0, C_14:0, anteiso-C_15:0 and iso-C_14:0. The three predominant menaquinones were identified as MK-6 (menaquinene-6), MMK-6 (monomethylmenaquinone-6) and DMMK-6 (dimethylmenaquinone-6). The polar lipids were found to be diphosphatidylglycerol, phosphatidylglycerol and four unidentified glycolipid. The DNA G+C content of strain CAT-2^T was 68.4 mol%. Phylogenetic analysis based on 16S rRNA gene sequence similarities showed that strain CAT-2^T belongs to the genus Gordonibacter, sharing the highest level of sequence homology with Gordonibacter pamelaeae DSM 19378^T (97.3 %). Combined phenotypic, chemotaxonomic and phylogenetic characteristics support the conclusion that the strain CAT-2^T represents a novel species, for which the name Gordonibacter faecihominis sp. nov. is proposed. The type strain is CAT-2^T (= KCTC 15204^T = JCM 16058^T).     

Mutant forms of Escherichia coli protein L25 unable to bind to 5S rRNA are incorporated efficiently into the ribosome in vivo

5S rRNA-binding ribosomal proteins of the L25 family are an evolutional acquisition of bacteria. Earlier we showed that (i) single replacements in the RNA-binding module of the protein of this family result in destabilization or complete impossibility to form a complex with 5S rRNA in vitro; (ii) ΔL25 ribosomes of Escherichia coli are less efficient in protein synthesis in vivo than the control ribosomes. In the present work, the efficiency of incorporation of the E. coli protein L25 with mutations in the 5S rRNA-binding region into the ribosome in vivo was studied. It was found that the mutations in L25 that abolish its ability to form the complex with free 5S rRNA do not prevent its correct and efficient incorporation into the ribosome. This is supported by the fact that even the presence of a very weakly retained mutant form of the protein in the ribosome has a positive effect on the activity of the translational machinery in vivo. All this suggests the existence of an alternative incorporation pathway for this protein into the ribosome, excluding the preliminary formation of the complex with 5S rRNA. At the same time, the stable L25-5S rRNA contact is important for the retention of the protein within the ribosome, and the conservative amino acid residues of the RNA-binding module play a key role in this.