Disease relevance of moaA

• Involvement of chlA, E, M, and N loci in Escherichia coli molybdopterin biosynthesis [1].
• The narA locus of Synechococcus sp. strain PCC 7942 consists of a cluster of molybdopterin biosynthesis genes [2].
• The Bacillus subtilis narA locus was shown to include narQ and narA [3].
• Cellular sensitivity to ethanol toxicity was unaffected by the integrated lambda fragment(s) or by an intact lambda prophage; but, it was increased by deletions of the E. coli chromosome extending rightward from bio into uvrB, and rightward from chlA [4].

High impact information on moaA

• The proteins encoded by the Escherichia coli genes moaA and moaC catalyse the first steps in MoCo synthesis [5].
• However, relative to modA, binding of ModE to the moaA promoter appeared to be largely molybdate independent both in vitro and in vivo [6].
• Footprint analysis of the moaA promoter revealed a single protected region located immediately upstream of the putative -35 consensus sequence and extending from position -202 to -174, relative to the start of translation [6].
• N-terminal amino acid sequences for the moaA, B, C and E products confirmed the translational starts [7].
• Genetic evidence is presented which strongly suggests that the molybdenum cofactor is a repressor of chlA expression [8].

Chemical compound and disease context of moaA

• Identification in various chlorate-resistant mutants of a protein involved in the activation of nitrate reductase in the soluble fraction of a chlA mutant of Escherichia coli K-12 [9].
• Because cnx68 and MA-2 lack the molybdenum cofactor required for nitrate reductase activity, these results indicate that the functional chlA gene is essential to produce the molybdenum cofactor in E. coli [10].

Biological context of moaA

• Selection for growth on nitrate under anaerobic conditions yielded four plasmids which complemented mutants of the chlA, B, E and G types [11].
• A clone containing a gene capable of complementing the chlA mutation SA493 was obtained on a large cosmid pJT1 [10].
• However, the cofactor from the chlA strain mediated the dimerization of the nit-1 subunits in the presence and absence of molybdate to yield the 7.9S dimer [12].
• Regulation of the nitrate reductase operon: effect of mutations in chlA, B, D and E genes [13].
• Through simultaneous selection for mutations in the two closely linked genes, gal and chlA, a variety of deletions of varying length, some extending through as much as 1 min of the chromosome, could be readily obtained [14].

Associations of moaA with chemical compounds

• Heat-treated preparations from chlA and chlE mutants which do not possess molybdenum cofactor activity fail to restore the activation [15].
• The partial purification of Protein PA has been achieved from various chlorate-resistant mutants (chlA-chlG) [9].
• Conversely, well characterized mutants in any of chlA, B, D, E, G and N were also able to use citrate anaerobically [16].
• The mixing of soluble fractions from chlA and chlB mutants grown under the appropriate conditions leads to the activation of nitrate reductase, formate benzyl-viologen oxidoreductase and trimethylamine-N-oxide reductase [17].

Other interactions of moaA

• Molybdopterin (MPT) is not produced by the Escherichia coli mutants chlA1, chlM, or chlN or by the Neurospora crassa mutant nit-1 [18].
• Mutations at the chlA or chlE locus, which are required for molybdenum cofactor biosynthesis, similarly do not affect the activity of the heat-treated extract in the in vitro activation process [19].

Analytical, diagnostic and therapeutic context of moaA

• Reconstitution of plant nitrate reductase by Escherichia coli extracts and the molecular cloning of the chlA gene of Escherichia coli K12 [10].
• The synthesis of nitrate reductase by a parental Escherichia coli K12 strain and its isogenic chlA and chlB mutants has been analyzed by protein double labelling with L-[4,5-3H]leucine and sulphur-35 and by immunoprecipitation using specific antiserum [20].

References