Open AccessThe cbiS Gene of the Archaeon Methanopyrus kandleri AV19 Encodes a Bifunctional Enzyme with Adenosylcobinamide Amidohydrolase and α-Ribazole-Phosphate Phosphatase Activities
Author(s) -
Jesse D. Woodson,
Jorge C. EscalanteSemerena
Publication year - 2006
Publication title -
journal of bacteriology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.652
H-Index - 246
eISSN - 1067-8832
pISSN - 0021-9193
DOI - 10.1128/jb.00227-06
Subject(s) - amidohydrolase , biology , escherichia coli , biochemistry , enzyme , gene , isozyme , phosphofructokinase 2 , phosphatase , alkaline phosphatase , microbiology and biotechnology
Here we report the initial biochemical characterization of the bifunctional α-ribazole-P (α-RP) phosphatase, adenosylcobinamide (AdoCbi) amidohydrolase CbiS enzyme from the hyperthermophilic methanogenic archaeonMethanopyrus kandleri AV19. ThecbiS gene encodes a 39-kDa protein with two distinct segments, one of which is homologous to the AdoCbi amidohydrolase (CbiZ, EC 3.5.1.90) enzyme and the other of which is homologous to the recently discovered archaeal α-RP phosphatase (CobZ, EC 3.1.3.73) enzyme. CbiS function restored AdoCbi salvaging and α-RP phosphatase activity in strains of the bacteriumSalmonella enterica where either step was blocked. The two halves of thecbiS genes retained their function in vivo when they were cloned separately. The CbiS enzyme was overproduced inEscherichia coli and was isolated to >95% homogeneity. High-performance liquid chromatography, UV-visible spectroscopy, and mass spectroscopy established α-ribazole and cobyric acid as the products of the phosphatase and amidohydrolase reactions, respectively. Reasons why the CbiZ and CobZ enzymes are fused in some archaea are discussed.