Identification and characterization of an archaeon-specific riboflavin kinase.
The riboflavin kinase in Methanocaldococcus jannaschii has been identified as the product of the MJ0056 gene. Recombinant expression of the MJ0056 gene in Escherichia coli led to a large increase in the amount of flavin mononucleotide (FMN) in the E. coli cell extract. The unexpected features of the purified recombinant enzyme were its use of CTP as the phosphoryl donor and the absence of a requirement for added metal ion to catalyze the formation of FMN. Identification of this riboflavin kinase fills another gap in the archaeal flavin biosynthetic pathway. Some divalent metals were found to be potent inhibitors of the reaction. The enzyme represents a unique CTP-dependent family of kinases.
Mashhadi
Zahra
Z
Department of Biochemistry, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061, USA.
Zhang
Hong
H
Xu
Huimin
H
White
Robert H
RH
D019843:Archaeal Proteins / Q000235:genetics / Q000378:metabolism*; D002850:Chromatography, Gel; D003570:Cytidine Triphosphate / Q000737:chemistry / Q000378:metabolism; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism; D005486:Flavin Mononucleotide / Q000737:chemistry / Q000378:metabolism; D017015:Methanococcales / Q000201:enzymology* / Q000235:genetics; D008954:Models, Biological; D015394:Molecular Structure; D017853:Phosphotransferases (Alcohol Group Acceptor) / Q000235:genetics / Q000378:metabolism*; D011994:Recombinant Proteins / Q000378:metabolism
D019843:Archaeal Proteins; D011994:Recombinant Proteins; D003570:Cytidine Triphosphate; D005486:Flavin Mononucleotide; D017853:Phosphotransferases (Alcohol Group Acceptor); C022532:riboflavin kinase