Crp of Streptomyces coelicolor is the third transcription factor of the large CRP-FNR superfamily able to bind cAMP

Abstract

The chromosomal inactivation of the unique transcription factor of Streptomyces coelicolor that displays a cyclic-nucleotide-binding domain, Crp(Sco), led to a germination-defective phenotype similar to the mutant of the adenylate cyclase gene (cya) unable to produce cAMP. By means of cAMP affinity chromatography we demonstrate the specific cAMP-binding ability of Crp(Sco), which definitely demonstrate that a Cya/cAMP/Crp system is used to trigger germination in S. coelicolor. However, electromobility shift assays with the purified Crp(Sco)-cAMP complex and the CRP-like cis-acting element of its own promoter failed. Moreover, we were unable to complement an Escherichia coli crp mutant in trans with Crp(Sco). The fact that Vfr from Pseudomonas aeruginosa and GlxR from Corynebacterium glutamicum could complement such an E. coli mutant suggests that the way Crp(Sco) interacts with DNA should mechanistically differ from its most similar members. This hypothesis was further supported by homology modelling of Crp(Sco) that confirmed an unusual organisation of the DNA-binding domain compared to the situation observed in Crp(Eco).

Transcription Activation Mediated by a Cyclic AMP Receptor Protein from Thermus thermophilus HB8

“…In addition, a helix-turn-helix DNA binding motif of the CRP/FNR family was identified in the carboxyterminal region of the TTHA1437 protein ( 162 F to 203 R). S. coelicolor CRP, which is the closest homolog of the TTHA1437 protein among the proteins with known functions, has been indicated to bind cAMP, and the residues that are involved in the cAMP binding have been predicted based on a threedimensional model of the S. coelicolor CRP (12). Based on the amino acid alignment shown in Fig.…”

“…Based on the amino acid alignment shown in Fig. 1 However, the residues involved in heme binding in CooA (71) are not present in the TTHA1437 protein, as in cases of S. coelicolor CRP and C. glutamicum GlxR, which also belong to the CooA subgroup, but are suggested to be cAMP receptor proteins (12,29).…”

“…The manner of the DNA recognition by T. thermophilus CRP may differ from that in the case of E. coli CRP because the left arm of the consensus T. thermophilus CRP-binding site differs from that of E. coli CRP, although the right arm block, 13 TCACA, might correspond to the 15 TCACA block of the E. coli consensus CRP-binding site. It should be noted that S. coelicolor CRP, one of the closer homologs of T. thermophilus CRP, did not recognize a DNA sequence similar to that of the E. coli CRP-binding site (12). The structure of the C-terminal DNA-binding domain of T. thermophilus CRP might differ from that of E. coli CRP, as predicted in the case of S. coelicolor CRP (12), even though 180 R, 181 E, and 185 R of E. coli CRP, which directly interact with DNA, are conserved in T. thermophilus CRP ( 177 R, 178 E, and 182 R).…”

“…(11), Vibrio cholerae (55), Pseudomonas aeruginosa (57), Syn-echocystis sp. strain PCC6803 (70), Corynebacterium glutamicum (29), Streptomyces coelicolor (12), and Mycobacterium tuberculosis (50). The consensus binding sequences of CRP homologs, such as C. glutamicum GlxR (36), M. tuberculosis Rv3676 (CRP Mt ) (1), H. influenzae CRP (7), and P. aeruginosa Vfr (28), are similar to that of E. coli CRP.…”

CbpA: a Polarly Localized Novel Cyclic AMP-Binding Protein in Pseudomonas aeruginosa

“…Genome sequencing and functional studies have demonstrated that the CRP family transcriptional regulators are widely distributed in gram-negative and gram-positive bacteria, where they regulate diverse processes. These pathways include phototaxis and heterocyst formation in cyanobacteria (36), anaerobic respiration in Shewanella oneidensis (41), germination and morphological development in Streptomyces coelicolor (12), Mycobacterium tuberculosis virulence in mice (40), quorum sensing and motility in Vibrio cholerae (29), and phytopathogenicity and cell-cell communication in Xanthomonas campestris (11,19).…”