title: The purMN genes of Rhizobium leguminosarum and a superficial link with siderophore production.
abstract: We isolated a mutant of R. leguminosarum initially on the basis of reduced production of the siderophore vicibactin on chrome azurol sulfonate (CAS)/agar indicator plates. The mutation was in the purMN operon and the mutant was shown to be an adenine auxotroph and defective for nodulation of peas. The siderophore defect appears to be trivial, being due to diminished growth of the auxotroph on agar-based minimal medium, which contains unknown contaminant(s) that allow it grow poorly. Transcriptional fusions showed that purMN was transcribed at relatively high levels in media containing purines. Expression was enhanced, approximately twofold, if purines were omitted.
authors.affiliation: School of Biological Sciences, University of East Anglia, Norwich, UK.
authors.forename: J B
authors.initials: JB
authors.lastname: Stevens
authors.forename: N G
authors.initials: NG
authors.lastname: de Luca
authors.forename: J E
authors.initials: JE
authors.lastname: Beringer
authors.forename: J P
authors.initials: JP
authors.lastname: Ringer
authors.forename: K H
authors.initials: KH
authors.lastname: Yeoman
authors.forename: A W
authors.initials: AW
authors.lastname: Johnston
mesh_terms: D004926:Escherichia coli / Q000235:genetics; D005798:Genes, Bacterial; D008969:Molecular Sequence Data; D009154:Mutation; D018532:Pisum sativum / Q000382:microbiology; D010456:Peptides, Cyclic / Q000096:biosynthesis; D010957:Plasmids / Q000235:genetics; D011687:Purines / Q000378:metabolism; D016961:Rhizobium leguminosarum / Q000235:genetics* / Q000378:metabolism*; D017262:Siderophores / Q000096:biosynthesis*
chemical_list: D010456:Peptides, Cyclic; D011687:Purines; D017262:Siderophores; C119259:vicibactin