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M S Gel'fand

Publications and source records attributed to M S Gel'fand.

At least 19 recordsLinked to original sources
PubMed2002

[Production of bacteriocins by gram-positive bacteria and the mechanisms of transcriptional regulation].

The mechanisms of production of bacteriocins in Gram-positive bacteria and the main distinctions of these bacteriocins from the bacteriocins of Gram-negative bacteria (colicins) are outlined. A classification of antibacterial peptides is presented, and most of known class I and II peptides are pointed out. In Gram-positive bacteria, the cases of bacteriocin-associated quorum sensing are examined. For these cases, the structure of loci containing the genes of regulatory systems, transport, immunity, processing, and posttranslational modification of antibacterial peptides are described. All known regulatory sites for class II bacteriocins are presented. A description of the putative regulatory sites found by us and their classification are provided. The evolutionary tree of transcriptional response regulators is shown to correspond to the tree of their recognition sites.

Bacteriocins↗
PubMed2002

[Regulation of transcription in the system of genes responsible for bacteriocins production in Streptococcus equi ].

Bacteriocin production in many Gram-positive bacteria is controlled by a two-component regulatory system that is composed of the sensor protein and the response regulator. In this work, methods of computer analysis were used to describe the locus of genes responsible for the synthesis of class II bacteriocins in the Streptococcus equi genome. Potential regulatory sites (direct repeats) recognized by a DNA-binding protein of the corresponding two-component system were predicted.

Amino Acid Sequence↗
PubMed2002

[Purine regulon of gamma-proteobacteria: a detailed description].

The structure of the purine regulon was studied by a comparative genomic approach in seven genomes of gamma-proteobacteria: Escherichia coli, Salmonella typhi, Yersinia pestis, Haemophilus influenzae, Pasteurella multocida, Actinobacillus actinomycetemcomitans, and Vibrio cholerae. The palindromic binding site of the purine repressor (consensus ACGCAAACGTTTGCGT) is fairly well retained of genes encoding enzymes that participate in the synthesis of inosinemonophosphate from phosphoribozylpyrophosphate and in transfer of unicarbon groups, and also upstream of some transport protein genes. These genes may be regarded as the main part of the purine regulon. In terms of physiology, the regulation of the purC and gcvTHP/folD genes seems to be especially important, because the PurR site was found upstream of nonorthologous but functionally replaceable genes. However, the PurR site is poorly retained in front of orthologs of some genes belonging to the E. coli purine regulon, such as genes involved in general nitrogen metabolism, biosynthesis of pyrimidines, and synthesis of AMP and GMP from IMP, and also upstream of the purine repressor gene. It is predicted that purine regulons of the examined bacteria include the following genes: upp participating in synthesis of pyrimidines; uraA encoding an uracil transporter gene; serA involved in serine biosynthesis; folD responsible for the conversion of N5,N10-methenyl tetrahydrofolate into N10-formyltetrahydrofolate; rpiA involved in ribose metabolism; and protein genes with an unknown function (yhhQ and ydiK). The PurR site was shown to have different structure in different genomes. Thus, the tendency for a decline of the conservatism of site positions 2 and 15 was observed in genomes of bacteria belonging to the Pasteurellaceae and Vibrionaceae groups.

Adenosine Monophosphate↗
PubMedDate not supplied

[Statistical analysis of the exon-intron structure of higher eukaryote genes].

The exon-intron structure of human, insect (Drosophila sp.), and dicot plant (Arabidopsis thaliana) genes was considered. In each genome there exists a characteristic intron length. Anomalously long introns was usually the first introns in genes. In each sample there are correlations between the lengths of neighboring exons and between exon lengths and closeness to the consensus of the sites at exon boundaries. Exons and exon pairs containing an integer number of triplets are preferred. These results are relevant to the study of splicing mechanism and evolution of introns, as well as construction of gene recognition algorithms.

Algorithms↗
PubMedDate not supplied

[Computer analysis of regulatory signals in complete bacterial genomes. Translation initiation of ribosomal protein operons].

Signals of translation initiation of operons of Haemophilus influenzae ribosomal proteins were predicted. This process is regulated by the formation of secondary RNA structures to which one of the proteins encoded in a particular operon binds. In some cases, these structures imitate the region of protein binding to rRNA. Predictions are made by comparing with homologous operons of Escherichia coli and analogous regions of rRNA and by estimating the energy of secondary structure formation. It is shown that this regulatory mechanism occurs: in operons L11, S10, S15, spc, and alpha of H.influenzae and, probably, in operon S15 of Helicobacter pylori, Bacillus subtilis, and Mycoplasma genitalium.

Base Sequence↗
PubMedDate not supplied

[Statistical analysis and prediction of bacterial sites for ribosomal binding].

An algorithm for recognition of prokaryotic ribosomal binding sites is suggested. The parameter library contains weight matrices for mapping of gene starts in various bacterial genomes. Comparison of the ribosome binding starts in different taxonomic groups demonstrates that the signals in Gram-positive bacteria are stronger than in Gram-negative bacteria, and in particular, Enterobacteria. The recognition matrices are available by e-mail misha@imb.imb.ac.ru.

Algorithms↗
PubMedDate not supplied

[Computer analysis of regulatory signals in bacterial genomes. Fnr binding segments].

Comparative approach to computer analysis of regulatory signals allows one to predict new signals in bacterial genomes with high accuracy. A prediction is reliable whenever candidate signals are consistently observed in several related genomes. We applied comparative approach to the analysis of the Fnr regulon of gamma-proteobacteria. Responding to changes in the aerobic/anaerobic state of the medium, the transcriptional factor Fnr regulates expression of many genes. We predicted Fnr binding-sites in 12 genes regulated by Fnr, and identified 17 new operons as potential members of the Fnr regulon of Escherichia coli. In addition, we described the Fnr regulon of other gamma-proteobacteria.

Bacterial Proteins↗
PubMedDate not supplied

[Study on regulation of long-chain fatty acid metabolism with the use of computer analysis of complete bacterial genomes].

One of the main trends in the prokaryote genomics is the comparative analysis of metabolic pathways. This method can be used for the analysis of experimentally studied systems of co-regulated genes, as well as genes with unknown regulatory signals. In this study we apply the comparative analysis of regulatory signals to the genes of the enzymes for fatty acid metabolism from Escherichia coli, Haemophilus influenzae, Vibrio cholerae, Yersinia pestis. Transcription of these genes is regulated by the FadR protein. We describe the FadR regulation of the long-chain fatty acid oxidation and partially that of the fatty acid biosynthesis. We also demonstrate that the gene yafH encoding acyl-CoA dehydrogenase is identical to the gene fadE, previously identified by genetic techniques.

Acyl-CoA Dehydrogenase↗