%0 Journal Article %T Computational prediction of cAMP receptor protein (CRP) binding sites in cyanobacterial genomes %A Minli Xu %A Zhengchang Su %J BMC Genomics %D 2009 %I BioMed Central %R 10.1186/1471-2164-10-23 %X We have predicted and analyzed the CRP binding sites and regulons in 12 sequenced cyanobacterial genomes using a highly effective cis-regulatory binding site scanning algorithm. Our results show that cyanobacterial CRP binding sites are very similar to those in E. coli; however, the regulons are very different from that of E. coli. Furthermore, CRP regulons in different cyanobacterial species/ecotypes are also highly diversified, ranging from photosynthesis, carbon fixation and nitrogen assimilation, to chemotaxis and signal transduction. In addition, our prediction indicates that crp genes in modern cyanobacteria are likely inherited from a common ancestral gene in their last common ancestor, and have adapted various cellular functions in different environments, while some cyanobacteria lost their crp genes as well as CRP binding sites during the course of evolution.The CRP regulons in cyanobacteria are highly diversified, probably as a result of divergent evolution to adapt to various ecological niches. Cyanobacterial CRPs may function as lineage-specific regulators participating in various cellular processes, and are important in some lineages. However, they are dispensable in some other lineages. The loss of CRPs in these species leads to the rapid loss of their binding sites in the genomes.Cyclic AMP receptor protein (CRP), also known as catabolite gene activator protein (CAP), is an important transcriptional regulator widely distributed in a variety of bacterial groups [1,2]. The biological processes under the regulation of CRP are highly diverse, including energy metabolism [3,4], cell division and development [5], toxin production [1], competence development [6], quorum sensing [7] and cellular motility [8,9]. CRP belongs to the CRP/FNR transcription factor (TF) superfamily [10], which are generally believed to function as global regulators throughout the eubacteria [11]. Each member of the CRP/FNR superfamily contains an N-terminal effector binding domain a %U http://www.biomedcentral.com/1471-2164/10/23