The nucleotide-binding site of HisP, a membrane protein of the histidine permease. Identification of amino acid residues photoaffinity labeled by 8-azido-ATP.

摘要: The periplasmic histidine transport system (permease) of Escherichia coli and Salmonella typhimurium is composed a soluble, histidine-binding receptor located in the periplasm complex three membrane-bound proteins which one, HisP, was shown previously to bind ATP. These permeases are energized by HisP member family membrane conserved all presumed be involved coupling energy ATP transport. In this paper nature ATP-binding site has been explored identification some residues that come into contact with derivatized 8-azido-ATP (N3ATP). Both underivatized forms were solubilized, purified, digested trypsin. resulting tryptic peptides resolved high pressure liquid chromatography, modified N3ATP isolated sequenced. Two peptides, X Z, spanning amino acid 16-23 31-45, found contain sites attachment at His19 Ser41, respectively. close amino-terminal end HisP; peptide Z one well regions comprising nucleotide-binding consensus motifs energy-coupling components these permeases. many purine proteins. relationship between location overall structure discussed.