共查询到20条相似文献,搜索用时 15 毫秒
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De Bie LG Roovers M Oudjama Y Wattiez R Tricot C Stalon V Droogmans L Bujnicki JM 《Journal of bacteriology》2003,185(10):3238-3243
We cloned, expressed, and purified the Escherichia coli YggH protein and show that it catalyzes the S-adenosyl-L-methionine-dependent formation of N(7)-methylguanosine at position 46 (m(7)G46) in tRNA. Additionally, we generated an E. coli strain with a disrupted yggH gene and show that the mutant strain lacks tRNA (m(7)G46) methyltransferase activity. 相似文献
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Katsumi Isono 《Molecular & general genetics : MGG》1978,165(3):265-268
Summary A mutant of Escherichia coli which was isolated for temperature-sensitive growth was found to harbour a structural alteration in protein S16 (Isono et al., 1978). The mutation was localized by matings with various Hfr strains and by Plkc-mediated transduction. The results showed that it mapped very close to the gene coding for L19 protein which has been placed at 56.4 min (Kitakawa and Isono, 1977), indicating that it most likely forms a new ribosomal protein-gene cluster. 相似文献
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C Ehresmann P Stiegler G A Mackie R A Zimmermann J P Ebel P Fellner 《Nucleic acids research》1975,2(2):265-278
Recent progress in the nucleotide sequence analysis of the 16S ribosomal RNA from E. coli is described. The sequence which has been partially or completely determined so far encompasses 1520 nucleotides, i.e. about 95% of the molecule. Possible features of the secondary structure are suggested on the basis of the nucleotide sequence and data on sequence heterogeneities, repetitions and the location of modified nucleotides are presented. In the accompanying paper, the use of the nucleotide sequence data in studies of the ribosomal protein binding sites is described. 相似文献
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The primary structure of protein L21 from the 50S subunit of Escherichia coli ribosomes has been completely determined by sequencing the peptides obtained by digestion of L21 with trypsin before and after modification of the arginine residues with 1,2-cyclohexanedione, Staphylococcus aureus protease, thermolysin, and pepsin. Automated Edman degradation using a liquid-phase sequenator was carried out on the intact protein as well as on a fragment arising from cleavage with cyanogen bromide. Protein L21 consists of a single polypeptide chain of 103 amino acids of molecular weight 11 565. An estimation of the secondary structure of protein L21 and a comparison with other E. coli ribosomal protein sequences are presented. 相似文献
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The Escherichia coli 30S ribosomal subunit; an optimized three-dimensional fit between the ribosomal proteins and the 16S RNA. 总被引:7,自引:2,他引:7
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We have generated a computerized fit between the 3-dimensional map of the E.coli 30S ribosomal proteins, as determined by neutron scattering, and the recently published 3-dimensional model for the 16S RNA. To achieve this, the framework of coordinates for RNA-protein cross-link sites on the phosphate backbone in the RNA model was related to the corresponding framework of coordinates for the mass centres of the proteins by a least squares fitting procedure. The resulting structure, displayed on a computer graphics system, gives the first complete picture of the E.coli 30S ribosomal subunit showing both the proteins and the double-helical regions of the RNA. The root mean square distance between cross-link sites and protein centres is 32 A. The position of the mass centre of the combined double-helical regions was calculated from the model and compared with the position of the mass centre of the complete set of proteins. The two centres are displaced relative to one another by 20 A in the model structure, in good agreement with the experimental value of 25 A found by neutron scattering. 相似文献
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Genetic fine structure of the pyrE region containing the genes for ribosomal proteins L28 and L33 in Escherichia coli 总被引:2,自引:0,他引:2
Katsumi Isono Joachim Schnier Madoka Kitakawa 《Molecular & general genetics : MGG》1980,179(2):311-317
Summary Temperature-sensitive mutants harbouring alterations in ribosomal proteins L28 and L33 have been isolated and used in mapping the genes coding for the two proteins. It was found that they mapped very close to each other and near pyrE at 80.7 min on the E. coli genetic map. The genes affected by the mutations have been concluded to be the structural genes for proteins L28 (rpmB) and L33 (rpmG) by constructing merodiploids heterozygous for pyrE and for the two ribosomal proteins. Various transduction studies with P1kc phages indicate the gene order in this region to be (rpmB, rpmG)-pyrE-spoT-gltC. 相似文献
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Sanjay Agarwalla James T Kealey Daniel V Santi Robert M Stroud 《The Journal of biological chemistry》2002,277(11):8835-8840
An Escherichia coli open reading frame, ygcA, was identified as a putative 23 S ribosomal RNA 5-methyluridine methyltransferase (Gustafsson, C., Reid, R., Greene, P. J., and Santi, D. V. (1996) Nucleic Acids Res. 24, 3756-3762). We have cloned, expressed, and purified the 50-kDa protein encoded by ygcA. The purified enzyme catalyzed the AdoMet-dependent methylation of 23 S rRNA but did not act upon 16 S rRNA or tRNA. A high performance liquid chromatography-based nucleoside analysis identified the reaction product as 5-methyluridine. The enzyme specifically methylated U1939 as determined by a nuclease protection assay and by methylation assays using site-specific mutants of 23 S rRNA. A 40-nucleotide 23 S rRNA fragment (nucleotide 1930--1969) also served as an efficient substrate for the enzyme. The apparent K(m) values for the 40-mer RNA oligonucleotide and AdoMet were 3 and 26 microm, respectively, and the apparent k(cat) was 0.06 s(-1). The enzyme contains two equivalents of iron/monomer and has a sequence motif similar to a motif found in iron-sulfur proteins. We propose to name this gene rumA and accordingly name the protein product as RumA for RNA uridine methyltransferase. 相似文献
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