TY - JOUR
T1 - Distinct physiological roles for the two l-asparaginase isozymes of Escherichia coli
AU - Srikhanta, Yogitha N.
AU - Atack, John M
AU - Beacham, Ifor R
AU - Jennings, Michael P
PY - 2013/7/5
Y1 - 2013/7/5
N2 - Escherichia coli expresses two l-asparaginase (EC 3.5.1.1) isozymes: l-asparaginse I, which is a low affinity, cytoplasmic enzyme that is expressed constitutively, and l-asparaginase II, a high affinity periplasmic enzyme that is under complex co-transcriptional regulation by both Fnr and Crp. The distinct localisation and regulation of these enzymes suggest different roles. To define these roles, a set of isogenic mutants was constructed that lacked either or both enzymes. Evidence is provided that l-asparaginase II, in contrast to l-asparaginase I, can be used in the provision of an anaerobic electron acceptor when using a non-fermentable carbon source in the presence of excess nitrogen.
AB - Escherichia coli expresses two l-asparaginase (EC 3.5.1.1) isozymes: l-asparaginse I, which is a low affinity, cytoplasmic enzyme that is expressed constitutively, and l-asparaginase II, a high affinity periplasmic enzyme that is under complex co-transcriptional regulation by both Fnr and Crp. The distinct localisation and regulation of these enzymes suggest different roles. To define these roles, a set of isogenic mutants was constructed that lacked either or both enzymes. Evidence is provided that l-asparaginase II, in contrast to l-asparaginase I, can be used in the provision of an anaerobic electron acceptor when using a non-fermentable carbon source in the presence of excess nitrogen.
KW - Anaerobic growth
KW - Asparaginase
KW - Escherichia coli
KW - Isozymes
UR - http://www.scopus.com/inward/record.url?scp=84879890306&partnerID=8YFLogxK
U2 - 10.1016/j.bbrc.2013.05.066
DO - 10.1016/j.bbrc.2013.05.066
M3 - Article
C2 - 23726917
AN - SCOPUS:84879890306
SN - 0006-291X
VL - 436
SP - 362
EP - 365
JO - Biochemical and Biophysical Research Communications
JF - Biochemical and Biophysical Research Communications
IS - 3
ER -