Description

IPR013324 is a RNA polymerase sigma factor, region 3/4-like.

<p>The bacterial core RNA polymerase complex, which consists of five subunits, is sufficient for transcription elongation and termination but is unable to initiate transcription. Transcription initiation from promoter elements requires a sixth, dissociable subunit called a sigma factor, which reversibly associates with the core RNA polymerase complex to form a holoenzyme [[cite:PUB00000061]]. RNA polymerase recruits alternative sigma factors as a means of switching on specific regulons. Most bacteria express a multiplicity of sigma factors. Two of these factors, sigma-70 (gene rpoD), generally known as the major or primary sigma factor, and sigma-54 (gene rpoN or ntrA) direct the transcription of a wide variety of genes. The other sigma factors, known as alternative sigma factors, are required for the transcription of specific subsets of genes.</p> <p>With regard to sequence similarity, sigma factors can be grouped into two classes, the sigma-54 and sigma-70 families. Sequence alignments of the sigma70 family members reveal four conserved regions that can be further divided into subregions eg. sub-region 2.2, which may be involved in the binding of the sigma factor to the core RNA polymerase; and sub-region 4.2, which seems to harbor a DNA-binding 'helix-turn-helix' motif involved in binding the conserved -35 region of promoters recognised by the major sigma factors [[cite:PUB00004340], [cite:PUB00002181]].</p> <p>The plastids of higher plants originating from an ancestral cyanobacterial endosymbiont also contain sigma factors that are encoded by a small family of nuclear genes. All plastid sigma factors belong to the superfamily of sigmaA/sigma70 and have sequences homologous to the conserved regions 1.2, 2, 3, and 4 of bacterial sigma factors [[cite:PUB00088319]].</p> <p>This entry represents regions 3 and 4 (or sigma3 and sigma4 domains) found in several sigma factors, often in conjunction with the sigma2 domain ([interpro:IPR013325]). Both regions 3 and 4 are present in Sigma70 [[cite:PUB00000942]], Sigma28 (FliA), and SigA [[cite:PUB00010042]], while region4 is also found in SigmaF [[cite:PUB00011848]] and RpoE. Regions 3 and 4 have a nucleotide-binding 3-helical core structure, consisting of a closed or partly open bundle with a right-handed twist. Some other nucleotide-binding proteins are thought to contain domains with a similar topology.</p>

This description is obtained from EB-eye REST.

Associated GO terms

Unable to find any GO terms for the transcript with the identifier.

Associated Lotus transcripts 14

Co-occuring domains 1

A list of co-occurring predicted domains within the L. japonicus gene space: