Presence of the molybdenum-cofactor in nitrate reductase-deficient mutant cell lines of Nicotiana tabacum

Characterization of Nitrate Reductase Deficient Mutants of Chlorella sorokiniana

“…This has been reported for MoCofactor in N. crassa (20), squash (1), tobacco (17), and Escherichia coli (19). The SDS-treatment (Table II).…”

Molybdenum Cofactor Biosynthesis

“…Not only the Cnx1 protein (4) but also its G domain alone (data not shown) is able to complement the E. coli mutant mogA, which shows that at least the G domain alone is functionally active. Characterization of Cnx1-related mutants from plants (11,12,13) and E. coli (9,11) showed that (a) the defect of the mutation could be overcome by high concentrations of molybdate in the growth media and (b) the mutants are still able to synthesize MPT but not active Moco, so that it was suggested that Cnx1 is probably involved in a late step of Moco biosynthesis distal to the formation of MPT, i.e. insertion of Mo into MPT.…”

“…Mutants in this locus are Moco-deficient but can be partially repaired by growth on high concentrations of molybdate (11). In Nicotiana plumbaginifolia, it was shown that mutants in the Mo-repairable cnxA-locus are principally able to synthesize MPT; however, they are unable to produce active Moco (12). Thus it was suggested that Cnx1 should be involved in the last step of Moco synthesis, i.e.…”

Mcp1 Encodes the Molybdenum Cofactor Carrier Protein in Chlamydomonas reinhardtii and Participates in Protection, Binding, and Storage Functions of the Cofactor

“…This cofactor is very unstable in vitro, and molybdenum readily dissociates from the cofactor complex, converting irreversibly into an inactive form such that molybdate stabilizes Moco (9,10). Other sulfhydryl-protecting agents stabilize Moco (10,11), whereas sulfhydryl-reactive inhibitors prevent the reconstituting activity of the cofactor (12), indicating the participation of free sulfhydryl groups in the reconstitution process.…”