Molecular analysis of a microaerobically induced operon required for hydrogenase synthesis in Rhizobium leguminosarum biovar viciae

摘要: Summary The nucleotide sequence (6138 bp) of a microaerobically inducible region (hupV/VI) from the Rhizobium leguminosarum bv. viciae hydrogenase gene cluster has been determined. Six genes, arranged as single operon, were identified, and designated hypA, B, F, C, D E based on similarities all them, except hypF, to genes pleiotropic operon (hyp) Escherichia coli. The products hypBFCDE identified by in vivo expression analysis E. coli, their molecular sizes consistent with those predicted sequence. Transposon Tn5 insertions into hypB, hypD hypE resulted R. mutants that lacked any activity symbiosis peas, but still able synthesize polypeptide for large subunit. HypA, HypB, HypF HypD contained CX2C motifs characteristic metal-binding proteins. In addition, HypB bore long histidine-rich stretch amino acids near N-terminus, suggesting possible role nickel binding this protein. product HypF, which was translationally coupled presented two cysteine (CX2CX81CX2C) capacity form zinc finger-like structures N-terminal third A metabolism relation synthesis is postulated proteins HypF.