Genetic analysis of the HAMP domain of the Aer aerotaxis sensor localizes flavin adenine dinucleotide-binding determinants to the AS-2 helix.

ABSTRACT: HAMP domains are signal transduction domains typically located between the membrane anchor and cytoplasmic signaling domain of the proteins in which they occur. The prototypical structure consists of two helical amphipathic sequences (AS-1 and AS-2) connected by a region of undetermined structure. The Escherichia coli aerotaxis receptor, Aer, has a HAMP domain and a PAS domain with a flavin adenine dinucleotide (FAD) cofactor that senses the intracellular energy level. Previous studies reported mutations in the HAMP domain that abolished FAD binding to the PAS domain. In this study, using random and site-directed mutagenesis, we identified the distal helix, AS-2, as the component of the HAMP domain that stabilizes FAD binding. AS-2 in Aer is not amphipathic and is predicted to be buried. M

SUBMITTER: Ma Q 

PROVIDER: S-EPMC538817 | biostudies-literature | 2005 Jan

REPOSITORIES: biostudies-literature