Structural basis of the transcriptional regulation of the proline utilization regulon by multifunctional PutA.

ABSTRACT: The multifunctional Escherichia coli proline utilization A (PutA) flavoprotein functions both as a membrane-associated proline catabolic enzyme and as a transcriptional repressor of the proline utilization genes putA and putP. To better understand the mechanism of transcriptional regulation by PutA, we have mapped the put-regulatory region, determined a crystal structure of the PutA ribbon-helix-helix domain (PutA52, a polypeptide corresponding to residues 1-52 of E. coli PutA) complexed with DNA, and examined the thermodynamics of DNA binding to PutA52. Five operator sites, each containing the sequence motif 5'-GTTGCA-3', were identified using gel-shift analysis. Three of the sites are shown to be critical for repression of putA, whereas the two other sites are important for repression of

SUBMITTER: Zhou Y 

PROVIDER: S-EPMC2665032 | biostudies-literature | 2008 Aug

REPOSITORIES: biostudies-literature