Structural characterization of Spo0E-like protein-aspartic acid phosphatases that regulate sporulation in bacilli.
Spore formation is an extreme response of many bacterial species to starvation. In the case of pathogenic species of Bacillus and Clostridium, it is also a component of disease transmission. Entry into the pathway of sporulation in Bacillus subtilis and its relatives is controlled by an expanded two-component system in which starvation signals lead to the activation of sensor kinases and phosphorylation of the master sporulation response regulator Spo0A. Accumulation of threshold concentrations of Spo0A approximately P heralds the commitment to sporulation. Countering the activities of the sensor kinases are phosphatases such as Spo0E, which dephosphorylate Spo0A approximately P and inhibit sporulation. Spo0E-like protein-aspartic acid-phosphate phosphatases, consisting of 50-90 residues, are conserved in sporeforming bacteria and unrelated in sequence to proteins of known structure. Here we determined the structures of the Spo0A approximately P phosphatases BA1655 and BA5174 from Bacillus anthracis using nuclear magnetic resonance spectroscopy. Each is composed of two anti-parallel alpha-helices flanked by flexible regions at the termini. The signature SQELD motif (SRDLD in BA1655) is situated in the middle of helix alpha2 with its polar residues projecting outward. BA5174 is a monomer, whereas BA1655 is a dimer. The four-helix bundle structure in the dimer is reminiscent of the phosphotransferase Spo0B and the chemotaxis phosphatase CheZ, although in contrast to these systems, the subunits in BA1655 are in head-to-tail rather than head-to-head apposition. The implications of the structures for interactions between the phosphatases and their substrate Spo0A approximately P are discussed.
Grenha
Rosa
R
Structural Biology Laboratory, Department of Chemistry, University of York, York YO10 5YW, United Kingdom.
Rzechorzek
Neil J
NJ
Brannigan
James A
JA
de Jong
Rob N
RN
Ab
Eiso
E
Diercks
Tammo
T
Truffault
Vincent
V
Ladds
Joanne C
JC
Fogg
Mark J
MJ
Bongiorni
Cristina
C
Perego
Marta
M
Kaptein
Robert
R
Wilson
Keith S
KS
Folkers
Gert E
GE
Wilkinson
Anthony J
AJ
D020816:Amino Acid Motifs; D000595:Amino Acid Sequence; D001408:Bacillus anthracis / Q000201:enzymology* / Q000235:genetics / Q000502:physiology; D001426:Bacterial Proteins / Q000737:chemistry* / Q000235:genetics / Q000502:physiology; D001483:Base Sequence; D004269:DNA, Bacterial / Q000235:genetics; D019281:Dimerization; D005798:Genes, Bacterial; D008958:Models, Molecular; D008969:Molecular Sequence Data; D019906:Nuclear Magnetic Resonance, Biomolecular; D010744:Phosphoric Monoester Hydrolases / Q000737:chemistry* / Q000235:genetics / Q000502:physiology; D020836:Protein Structure, Quaternary; D017433:Protein Structure, Secondary; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics; D017386:Sequence Homology, Amino Acid; D013171:Spores, Bacterial / Q000201:enzymology / Q000235:genetics / Q000502:physiology
D001426:Bacterial Proteins; D004269:DNA, Bacterial; D011994:Recombinant Proteins; C030069:spore-specific proteins, Bacillus; C445331:aspartyl phosphate phosphatase; D010744:Phosphoric Monoester Hydrolases