Disease relevance of putA

• Effect of a Sinorhizobium meliloti strain with a modified putA gene on the rhizosphere microbial community of alfalfa [1].
• Sinorhizobium meliloti putA gene regulation: a new model within the family Rhizobiaceae [2].
• Therefore, the model of S. meliloti putA regulation completely diverges from that of its Rhizobiaceae relatives and resembles more that of enteric bacteria [2].
• In Rhodobacter capsulatus, Agrobacterium, and most probably in Bradyrhizobium, this activation is dependent on an Lrp-like protein encoded by the putR gene, located immediately upstream of putA [2].

High impact information on putA

• M403, a Sinorhizobium meliloti strain with enhanced competitiveness for nodule occupancy, was recently constructed by introducing a plasmid containing an extra copy of a modified putA (proline dehydrogenase) gene [1].
• In Sinorhizobium meliloti, as in other microorganisms, the putA gene is transcriptionally activated in response to proline [2].
• However, some differences have been found with the latter model: (i) S. meliloti putA gene is not catabolite repressed, and (ii) the gene encoding for the major proline permease (putP) does not form part of an operon with the putA gene [2].

Biological context of putA

• We found that the presence of multicopy plasmids containing this putA gene construct increased the competitiveness of S. meliloti in microcosm experiments in nonsterile soil planted with alfalfa plants subjected to drought stress only during the first month [3].

Associations of putA with chemical compounds

• Furthermore, results obtained with an S. meliloti putA null mutation indicate the absence of any proline-responsive transcriptional activator and that PutA serves as an autogenous repressor [2].

References