sigma factor

sig·ma fac·tor

a factor that inhibits the nonspecific DNA binding of RNA polymerase, as well as helping to identify the starting point of transcription; it promotes attachment of the RNA polymerase to specific initiation sites. Synonym(s): σ factor

sigma factor

n. A protein component of bacterial RNA polymerase that recognizes the correct site on DNA for initiating transcription of a gene and that is usually released soon after transcription begins.

sigma factor

a subunit of RNA polymerase that determines the site where transcription begins. The sigma factor confers PROMOTER specificity, assisting the RNA polymerase in recognising the correct promoter sequence on the DNA to initiate transcription. In ESCHERICHIA COLI the principal sigma factor is σ70, the housekeeping factor (see HOUSEKEEPING GENES).There are alternative sigma factors governing the expression of genes in response to different environmental conditions; for example σ38, the STATIONARY PHASE factor, and σ32, the heat shock factor (see HEAT SHOCK PROTEIN). These factors can associate with the RNA polymerase, displacing σ70 and directing the enzyme to initiate transcription from other promoters. see ANTISIGMA FACTOR.

单词	sigma factor
释义	sigma factor sigma factor n. A protein component of bacterial RNA polymerase that recognizes the correct site on DNA for initiating transcription of a gene and that is usually released soon after transcription begins. Translations sigma factor sigma factor [′sig·mə ‚fak·tər] (cell and molecular biology) A regulatory protein in prokaryotes that combines with the ribonucleic acid (RNA) polymerase enzyme to facilitate the initiation of RNA synthesis. sigma factor sig·ma fac·tor a factor that inhibits the nonspecific DNA binding of RNA polymerase, as well as helping to identify the starting point of transcription; it promotes attachment of the RNA polymerase to specific initiation sites. Synonym(s): σ factor sigma factor n. A protein component of bacterial RNA polymerase that recognizes the correct site on DNA for initiating transcription of a gene and that is usually released soon after transcription begins. sigma factor a subunit of RNA polymerase that determines the site where transcription begins. The sigma factor confers PROMOTER specificity, assisting the RNA polymerase in recognising the correct promoter sequence on the DNA to initiate transcription. In ESCHERICHIA COLI the principal sigma factor is σ70, the housekeeping factor (see HOUSEKEEPING GENES).There are alternative sigma factors governing the expression of genes in response to different environmental conditions; for example σ38, the STATIONARY PHASE factor, and σ32, the heat shock factor (see HEAT SHOCK PROTEIN). These factors can associate with the RNA polymerase, displacing σ70 and directing the enzyme to initiate transcription from other promoters. see ANTISIGMA FACTOR.
随便看	food biological agent detection sensor food biotechnology communications network food bodies food body food borne food-borne foodborne foodborne and diarrheal diseases branch foodborne and diarrheal diseases laboratory foodborne botulism food borne disease food-borne disease foodborne disease outbreak foodborne disease outbreak surveillance system food borne illness food-borne illness foodborne illness food-borne illness education information center foodborne illness outbreak response protocol foodborne outbreak response coordinating group food-borne parasite foodborne parasite foodborne pathogen foodborne pathogenic microorganisms & natural toxins handbook foodborne viruses in europe