E coli sigma factors recognize promoters with different consensus quences. Numbers in the name of a factor indicate its mass) Gene Factor Use -35 Sequence Separation 10 Sequence D 70 gener TTGACA 16-18b TATAAT rpoH heat shock CCCTTGAA 13-15 bp CCCGATNT rpoE heat shock not known not known not known rpoN nitrogen CTGGNA 6 bp TTGCA flagellar CTAAA 15 bp GCCGATAA A map of the E coli o70 factor Core enzyme identifies conserved binding Melting regions. Regions 2. 1 and 2.2 个个 contact core polymerase. 2. 3 N-terminus 200 600 is required for melting, and 2. 4 and 4.2 contact the-10 1.1 1.2 2.124 4.14.2 Interactions with promoter and-35 promotor elements The N-terminal Prevents DNA-binding region prevents 2. 4 and 4.2 from binding to dNa in the 10 TAATAT ACAGTT 5 absence of core enzymeA map of the E.coli σ 70 factor identifies conserved regions.Regions 2.1 and 2.2 contact core polymerase,2.3 is required for melting,and 2.4 and 4.2 contact the -10 and -35 promotor elements.The N-terminal region prevents 2.4 and 4.2 from binding to DNA in the absence of core enzyme. E.colisigma factors recognize promoters with different consensus sequences.(Numbers in the name of a factor indicate its mass)