Fig 1.

The YehU/YehT system of E. coli. (A) The region between 47.48 and 47.77 centisomes (bp 2202618 to 2217503) around the yehUT locus on the E. coli MG1655 chromosome is shown. See the text for a description of the neighboring genes. Arrows mark transcription start sites as indicated by EcoCyc (www.ecocyc.org) (32). Bar, 500 bp. (B) Domain structures of YehU and YehT. YehU is a class I HK in which DHp and CA domains are connected (30). The input domain of YehU consists of the 5TM Lyt (LytS-YhcK) domain (2) and a GAF domain. The G1 box of YehU is incomplete (G1*). YehT is made up of a CheY-like receiver domain and a LytTR-type DNA-binding domain (44). The phosphorylation sites are indicated (H, His; D, Asp). N, G1, F, and G2 are conserved boxes in HKs; CM, cytoplasmic membrane.