title: A histidine binding protein ofEscherichia coli: a component of cystine binding protein ofEscherichia coli.
abstract: Commercially obtained cystine binding protein (CBP), an osmotic shock protein ofEscherichia coli, was studied in an effort to determine its binding characteristics. Sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS/PAGE) analysis of commercially obtained CBP showed three protein bands. N-terminal amino acid microsequencing and subsequent computer search revealed that the sequence of one of these proteins (25-kDa) was nearly identical to histidine binding protein (HisJ) ofSalmonella typhimurium. Purification of CBP by HPLC yielded four protein peaks, of which one bound histidine exclusively. Binding was maximal at pH 5.0 to 6.0, at 4°C, did not require calcium or magnesium ions and was not inhibited by reduction of CBP disulfide bonds. Amino acids other than histidine or cystine did not bind to CBP. These data show that commercially available CBP is not a homogenous protein; it contains a histidine as well as a cystine binding component.
authors.affiliation: Unit on Genetic Diseases Involving Sulfur Metabolism, Human Genetics Branch, National Institute of Child Health and Human Development, Bldg. 10, Rm. 10N308, 20892, Bethesda, MD, USA.
authors.forename: J D
authors.initials: JD
authors.lastname: Butler
authors.forename: S W
authors.initials: SW
authors.lastname: Levin
authors.forename: A
authors.initials: A
authors.lastname: Facchiano
authors.forename: A B
authors.initials: AB
authors.lastname: Mukherjee