An acetyl-CoA synthetase not encoded by the facA gene is expressed under carbon starvation in Phycomyces blakesleeanus.
Two forms of acetyl-CoA synthetase (ACS1 and ACS2) have been detected in Phycomyces blakesleeanus. ACS1, encoded by the gene facA, was induced by acetate and repressed by glucose at the transcriptional level. ACS2, not encoded by the gene facA, was detected as a response to carbon starvation both in the wild type and in an facA(-) mutant. Both enzymes were purified and characterized. They can use acetate and propionate as substrates. ACS2 is a much more stable enzyme than ACS1. After 60 min incubation at 55 degrees C, ACS2 retained 50% of its activity whereas ACS1 only retained 3%. The optimum temperature was 50 degrees C for ACS2 and 30 degrees C for ACS1.
De Cima
Sergio
S
Departamento de Bioquímica y Biología Molecular, Universidad de León, Campus de Vegazana, 24007 León, Spain.
Rúa
Javier
J
Perdiguero
Eusebio
E
del Valle
Pilar
P
Busto
Félix
F
Baroja-Mazo
Alberto
A
de Arriaga
Dolores
D
D019342:Acetic Acid / Q000378:metabolism; D015152:Blotting, Northern; D003066:Coenzyme A Ligases / Q000096:biosynthesis* / Q000235:genetics / Q000302:isolation & purification; D004795:Enzyme Stability; D015966:Gene Expression Regulation, Fungal; D006358:Hot Temperature; D007700:Kinetics; D010800:Phycomyces / Q000201:enzymology*; D011422:Propionates / Q000378:metabolism; D012331:RNA, Fungal / Q000032:analysis; D012333:RNA, Messenger / Q000032:analysis; D013379:Substrate Specificity; D013696:Temperature; D013997:Time Factors
D011422:Propionates; D012331:RNA, Fungal; D012333:RNA, Messenger; D003066:Coenzyme A Ligases; C101958:acetate-CoA ligase (ADP-forming); C029658:propionic acid; D019342:Acetic Acid