PERSONAL DE APOYO
DIAZ Alejandra Raquel
artículos
Título:
Bacillus subtilis RapA phosphatase domain interaction with its substrate Spo0F~P and inhibitor PhrA peptide
Autor/es:
DIAZ AR, CORE LJ, JIANG M, MORELLI M, CHIANG CH, SZURMANT H, PEREGO M.
Revista:
JOURNAL OF BACTERIOLOGY
Editorial:
AMER SOC MICROBIOLOGY
Referencias:
Año: 2012 p. 147 - 164
ISSN:
0021-9193
Resumen:
ABSTRACT
Rap proteins in Bacillus subtilis regulate the phosphorylation level or the DNA-binding
activity of response regulators such as Spo0F, involved in sporulation initiation, or ComA,
regulating competence development. Rap proteins can be inhibited by specific peptides
generated by the export-import processing pathway of the Phr proteins. Rap proteins have a
modular organization comprising an amino terminal alpha-helical domain connected to a
domain formed by six tetratricopeptide (TPR) repeats. In this study, the molecular basis for
the specificity of the RapA phosphatase for its substrate Spo0F~P and its inhibitor
pentapeptide PhrA was analyzed in part by generating chimeric proteins with RapC that
targets the DNA-binding domain of ComA, rather than Spo0F~P, and is inhibited by the
PhrC pentapeptide. In vivo analysis of sporulation efficiency or competence-induced gene
expression as well as in vitro biochemical assays allowed the identification of the amino
terminal sixty amino acids as sufficient to determine Rap specificity for its substrate and the
central TPR3-5 repeats as providing binding specificity toward the Phr peptide inhibitor. The
results allowed the prediction and testing of key residues in RapA that are essential for PhrA
binding and specificity, thus demonstrating how the widespread structural fold of the TPR
repeat is highly versatile to use a common interaction mechanism for a variety of functions in
eukaryotic and prokaryotic organisms.