TY - JOUR
T1 - Low-molecular-weight protein tyrosine phosphatases of Bacillus subtilis
AU - Musumeci, Lucia
AU - Bongiorni, Cristina
AU - Tautz, Lutz
AU - Edwards, Robert A.
AU - Osterman, Andrei
AU - Perego, Marta
AU - Mustelin, Tomas
AU - Bottini, Nunzio
PY - 2005/7
Y1 - 2005/7
N2 - In gram-negative organisms, enzymes belonging to the low-molecular-weight protein tyrosine phosphatase (LMPTP) family are involved in the regulation of important physiological functions, including stress resistance and synthesis of the polysaccharide capsule. LMPTPs have been identified also in gram-positive bacteria, but their functions in these organisms are presently unknown. We cloned two putative LMPTPs from Bacillus subtilis, YfkJ and YwIE, which are highly similar to each other in primary structure as well as to LMPTPs from gram-negative bacteria. When purified from overexpressing Escherichia coli strains, both enzymes were able to dephosphorylate p-nitrophenyl-phosphate and phosphotyrosine-containing substrates in vitro but showed significant differences in kinetic parameters and sensitivity to inhibitors. Transcriptional analyses showed that yfkJ was transcribed at a low level throughout the growth cycle and underwent a σB-dependent transcriptional upregulation in response to ethanol stress. The transcription of ywlE was growth dependent but stress insensitive. Genomic deletion of each phosphatase-encoding gene led to a phenotype of reduced bacterial resistance to ethanol stress, which was more marked in the ywlE deletion strain. Our study suggests that YfkJ and YwlE play roles in B. subtilis stress resistance.
AB - In gram-negative organisms, enzymes belonging to the low-molecular-weight protein tyrosine phosphatase (LMPTP) family are involved in the regulation of important physiological functions, including stress resistance and synthesis of the polysaccharide capsule. LMPTPs have been identified also in gram-positive bacteria, but their functions in these organisms are presently unknown. We cloned two putative LMPTPs from Bacillus subtilis, YfkJ and YwIE, which are highly similar to each other in primary structure as well as to LMPTPs from gram-negative bacteria. When purified from overexpressing Escherichia coli strains, both enzymes were able to dephosphorylate p-nitrophenyl-phosphate and phosphotyrosine-containing substrates in vitro but showed significant differences in kinetic parameters and sensitivity to inhibitors. Transcriptional analyses showed that yfkJ was transcribed at a low level throughout the growth cycle and underwent a σB-dependent transcriptional upregulation in response to ethanol stress. The transcription of ywlE was growth dependent but stress insensitive. Genomic deletion of each phosphatase-encoding gene led to a phenotype of reduced bacterial resistance to ethanol stress, which was more marked in the ywlE deletion strain. Our study suggests that YfkJ and YwlE play roles in B. subtilis stress resistance.
UR - http://www.scopus.com/inward/record.url?scp=21844476149&partnerID=8YFLogxK
U2 - 10.1128/JB.187.14.4945-4956.2005
DO - 10.1128/JB.187.14.4945-4956.2005
M3 - Article
C2 - 15995210
AN - SCOPUS:21844476149
VL - 187
SP - 4945
EP - 4956
JO - Journal of Bacteriology
JF - Journal of Bacteriology
SN - 0021-9193
IS - 14
ER -