The anamorphic genus Calcarisporiella is a new member of the Mucoromycotina

The phylogenetic position of the anamorphic genus Calcarisporiella was investigated. Three isolates of Calcarisporiella, including an authentic strain and a newly obtained isolate, were analyzed phylogenetically using rDNA sequences. The result indicated that Calcarisporiella, which was classified as an ascomycetous anamorph, is a member of Mucoromycotina. It formed an independent clade separated from the other known orders of this subphylum.     

直立介蕨是假蹄盖蕨属的成员

对直立介蕨Dryoathyrium erectum (Z. R. Wang) W. M. Chu &; Z. R. Wang与介蕨属Dryoathyrium、假蹄盖蕨属Athyriopsis的叶、毛、孢子囊群和孢子的形态进行了比较研究。直立介蕨叶轴和羽轴上的沟槽不明显、具有单列细胞的节状毛、孢子囊群有双生一脉, 以及孢子的形态等特征与假蹄盖蕨属植物相似。结合叶绿体DNA trnL-F区序列分析结果, 所有形态及分子资料均表明该种植物应属于假蹄盖蕨属, 应恢复其原名直立假蹄盖蕨Athyriopsis erectum Z. R. Wang。     

A human T cell-specific molecule is a member of a new gene family

We have used a cDNA library enriched for T cell-specific sequences to isolate genes expressed by T cells but not by other cell types. We report here one such gene, designated RANTES, which encodes a novel T cell-specific molecule. The RANTES gene product is predicted to be 10 kDa and, after cleavage of the signal peptide, approximately 8 kDa. Of the 68 residues, 4 are cysteines, and there are no sites for N-linked glycosylation. RANTES is expressed by cultured T cell lines that are Ag specific and growth factor dependent. RANTES expression is inducible in PBL by Ag or mitogen. In CTL, expression of RANTES decreases after stimulation with Ag and growth factors. Interestingly, RANTES was not expressed by any T cell tumor line tested. There is significant homology between the RANTES sequence and several other T cell genes, suggesting that they comprise a previously undescribed family of small T cell molecules.     

A chloroplastic RNA-binding protein is a new member of the PPR family

P67, a new protein binding to a specific RNA probe, was purified from radish seedlings [Echeverria, M. and Lahmy, S. (1995) Nucleic Acids Res. 23, 4963–4970]. Amino acid sequence information obtained from P67 microsequencing allowed the isolation of genes encoding P67 in radish and Arabidopsis thaliana. Immunolocalisation experiments in transfected protoplasts demonstrated that this protein is addressed to the chloroplast. The RNA-binding activity of recombinant P67 was found to be similar to that of the native protein. A significant similarity with the maize protein CRP1 [Fisk, D.G., Walker, M.B. and Barkan, A. (1999) EMBO J. 18, 2621–2630] suggests that P67 belongs to the PPR family and could be involved in chloroplast RNA processing.     

Aeromonas allosaccharophila sp. nov., a new mesophilic member of the genus Aeromonas

Phenotypic and genetic studies were performed on some atypical aeromonas strains of uncertain taxonomic position. 16S rRNA gene sequence analysis revealed that these strains represent a hitherto unknown genetic line within the genus Aeromonas, for which the name Aeromonas allosaccharophila sp. nov. is proposed. The type strain is CECT 4199.     

A staphylococcal multidrug resistance gene product is a member of a new protein family.

The complete nucleotide sequence (321 bp) of smr (staphylococcal multidrug resistance), a gene coding for efflux-mediated multidrug resistance of Staphylococcus aureus, was determined by using two different plasmids as DNA templates. The smr gene product (identical to products of ebr and qacC/D genes) was shown to be homologous to a new family of small membrane proteins found in Escherichia coli, Pseudomonas aeruginosa, Agrobacterium tumefaciens, and Proteus vulgaris. The smr gene was subcloned and expressed in S. aureus and E. coli and its ability to confer the multidrug resistant phenotype was demonstrated for two different lipophilic cation classes: phosphonium derivatives and quarternary amines. Expression of smr gene leads to the efflux of tetraphenylphosphonium and to a net decrease in the uptake of lipophilic cations. The deduced polypeptide sequence (107 amino acid residues, 11,665 kDa) has 46% hydrophobic residues (Phe, Ile, Leu, and Val) and 20% hydroxylic residues (Ser and Thr). Four transmembrane segments are predicted for smr gene product. Of the charged amino acid residues, only Glu 13 is located in a transmembrane segment. This Glu 13 is conserved in all members of the family of small membrane proteins. We propose a mechanism whereby exchange of protons at the Glu 13 is a key in the efflux of the lipophilic cation. This mechanism includes the idea that protons are transported to the Glu 13 via an appropriate chain of hydroxylic residues in the transmembrane segments of Smr.     

A monocarboxylate permease of Rhizobium leguminosarum is the first member of a new subfamily of transporters

Amino acid transport by Rhizobium leguminosarum is dominated by two ABC transporters, the general amino acid permease (Aap) and the branched-chain amino acid permease (Bra). However, mutation of these transporters does not prevent this organism from utilizing alanine for growth. An R. leguminosarum permease (MctP) has been identified which is required for optimal growth on alanine as a sole carbon and nitrogen source. Characterization of MctP confirmed that it transports alanine (K(m) = 0.56 mM) and other monocarboxylates such as lactate and pyruvate (K(m) = 4.4 and 3.8 micro M, respectively). Uptake inhibition studies indicate that propionate, butyrate, alpha-hydroxybutyrate, and acetate are also transported by MctP, with the apparent affinity for solutes demonstrating a preference for C3-monocarboxylates. MctP has significant sequence similarity to members of the sodium/solute symporter family. However, sequence comparisons suggest that it is the first characterized permease of a new subfamily of transporters. While transport via MctP was inhibited by CCCP, it was not apparently affected by the concentration of sodium. In contrast, glutamate uptake in R. leguminosarum by the Escherichia coli GltS system did require sodium, which suggests that MctP may be proton coupled. Uncharacterized members of this new subfamily have been identified in a broad taxonomic range of species, including proteobacteria of the beta-subdivision, gram-positive bacteria, and archaea. A two-component sensor-regulator (MctSR), encoded by genes adjacent to mctP, is required for activation of mctP expression.     

Staphylococcus aureus aminopeptidase S is a founding member of a new peptidase clan

Staphylococcus aureus aminopeptidase S (AmpS) has been named for its predicted, but experimentally untested, aminopeptidase activity. The enzyme is homologous to biochemically characterized aminopeptidases that contain two cobalt or zinc ions in their active centers, but it is unrelated to all structurally characterized metallopeptidases. Here, we demonstrate AmpS aminopeptidase activity experimentally, and we present the 1.8-A crystal structure of the enzyme. Two metal ions with full occupancy and a third metal ion with low occupancy are present in the active site. A water molecule and Glu-319 serve as bridging ligands to the two metals with full occupancy. One of these metal ions is additionally coordinated by Glu-253 and His-348 and the other by His-381 and Asp-383. In addition, the metals are involved in weak metal-donor interactions to a water molecule and to Tyr-355. In the crystal, AmpS forms a dimer with a large internal cavity. The active sites are located at opposite ends of this internal cavity and are essentially inaccessible from the outside, suggesting that an inactive conformation was crystallized. Because gel filtration and analytical ultracentrifugation data also suggest dimer formation, the problem of substrate access to the active site cavity remains unresolved.     

Calexcitin B is a new member of the sarcoplasmic calcium-binding protein family

Calexcitin (CE) is a calcium sensor protein that has been implicated in associative learning. The CE gene was previously cloned from the long-finned squid, Loligo pealei, and the gene product was shown to bind GTP and modulate K(+) channels and ryanodine receptors in a Ca(2+)-dependent manner. We cloned a new gene from L. pealei, which encodes a CE-like protein, here named calexcitin B (CE(B)). CE(B) has 95% amino acid identity to the original form. Our sequence analyses indicate that CEs are homologous to the sarcoplasmic calcium-binding protein subfamily of the EF-hand superfamily. Far and near UV circular dichroism and nuclear magnetic resonance studies demonstrate that CE(B) binds Ca(2+) and undergoes a conformational change. CE(B) is phosphorylated by protein kinase C, but not by casein kinase II. CE(B) does not bind GTP. Western blot experiments using polyclonal antibodies generated against CE(B) showed that CE(B) is expressed in the L. pealei optic lobe. Taken together, the neuronal protein CE represents the first example of a Ca(2+) sensor in the sarcoplasmic calcium-binding protein family.     

Deodorization of pig feces by actinomycetes.

A medium composed of nutrient broth, 1.8% boric acid, and 1% sodium chloride at pH 7.0 was shown to maintain the stability of Escherichia coli cultures for up to 10 days at room temperature. By using this preservation medium for preparing a simulated sample a successful proficiency test survey in water bacteriology was conducted.     

Campylobacter anatolicus sp. nov., a novel member of the genus Campylobacter isolated from feces of Anatolian Ground Squirrel (Spermophilus xanthoprymnus) in Turkey

Seventy-four Gram-negative, motile, slightly curved rod-shaped, microaerophilic, oxidase-positive and catalase-negative isolates, recovered from fecal samples of the Anatolian ground squirrel (Spermophilus xanthoprymnus) in Kayseri, Turkey, were subjected to a polyphasic taxonomic study. Results of a genus-specific PCR indicated that all isolates belonged to the genus Campylobacter. 16S rRNA gene sequence analyses revealed the closest match as Campylobacter curvus DSM 6644^T with identity levels of 96.41–96.70%. Based on the 16S rRNA gene phylogeny of the 74 isolates, six isolates (faydin-G24, faydin-G52, faydin-G105, faydin-G114, faydin-G129 and faydin-G140^T) were chosen as representatives for further characterization. The overall genome relatedness indices for the strain faydin-G140^T, compared to the most closely related type strain C. curvus ATCC 35224^T, were calculated as 15.2%, 72.5%, and 83.7% for digital DNA-DNA hybridization (dDDH), and average nucleotide identity (ANIb and ANIm), respectively. The G+C content and genome size of the strains ranged between 35.2–35.4 mol% and 1.7–1.8 Mb, respectively. Based on data obtained from the polyphasic taxonomy approach, including phenotypic characterization as well as genomic and chemotaxonomic analyses, these strains are concluded to represent a novel species, for which the name Campylobacter anatolicus sp. nov. is proposed with faydin-G140^T as the type strain (=DSM 112311^T = LMG 32238^T).     

Isolation of Fc receptor shed from pig lymphocytes by a temperature shift

Lymphocytes obtained from pig blood by gradient centrifugation were subjected to a temperature shift (4 to 37 degrees C). The proteins released from the plasma membrane were fractionated by affinity chromatography using immunoglobulin G immobilized on fine polyamide particles. The main component liberated from the adsorbent by diethylamine buffer (pH 11.5) exhibited an apparent Mr of 18000-20000 in SDS-polyacrylamide gel electrophoresis. This crude receptor preparation possessed a substantially higher affinity to immobilized immunoglobulin G than to immobilized Fab fragment and inhibited significantly the binding of labeled immunoglobulin G to pig lymphocytes.     

A new diagnostic tool for neurocysticercosis is a member of a cestode specific hydrophobic ligand binding protein family

A protein of unknown function has been identified as a key serological tool for diagnosis of human tapeworm neurocysticercosis, a major worldwide neurological disease. Our own sequence analysis predicts that this protein is a member of a newly identified cestode specific oligomeric hydrophobic ligand binding protein family. In this report, using a rat cestode model, we confirm that homologues of this protein can bind fatty acids and their derivatives, and thus suggest a biological function for this key diagnostic tool.     

Rosmarinic acid synthase is a new member of the superfamily of BAHD acyltransferases

Purification of rosmarinic acid synthase (hydroxycinnamoyl-CoA:hydroxyphenyllactate hydroxycinnamoyltransferase) from suspension cells of Coleus blumei Benth. (Lamiaceae) by fractionated ammonium sulphate precipitation, hydrophobic interaction chromatography and two affinity chromatography steps led to the identification of peptide sequences, which enabled a PCR-based approach to isolate the full-length cDNA encoding this enzyme. The open reading frame of the cDNA had a length of 1290 base pairs encoding a protein of 430 amino acid residues with a molecular mass of 47,932 Da with typical characteristics of an acyltransferase of the BAHD superfamily. The cDNA was heterologously expressed in Escherichia coli. The enzyme displayed the activity of rosmarinic acid synthase using 4-coumaroyl- and caffeoyl-coenzyme A and 4-hydroxyphenyllactate as well as 3.4-dihydroxyphenyllactate as substrates. Shikimic acid and quinic acid were not able to serve as hydroxycinnamoyl acceptors. This therefore is the first report of the cDNA-cloning of a rosmarinic acid synthase.