2024-03-28T20:17:46Zhttp://digital.csic.es/dspace-oai/requestoai:digital.csic.es:10261/240152016-02-16T07:11:29Zcom_10261_22com_10261_1col_10261_275
2010-05-07T07:54:40Z
urn:hdl:10261/24015
Adenosine 5'-tetraphosphate and adenosine 5'-pentaphosphate are synthesized by yeast acetyl coenzyme A synthetase
Guranowski, Andrzej
Günther Sillero, María A.
Sillero, Antonio
5 pages, 2 figures.
Yeast (Saccharomyces cerevisiae) acetyl coenzyme A (CoA) synthetase (EC 6.2.1.1) catalyzes the synthesis of adenosine 5'-tetraphosphate (P4A) and adenosine 5'-pentaphosphate (p5A) from ATP and tri- or tetrapolyphosphate (P3 or P4), with relative velocities of 7:1, respectively. Of 12 nucleotides tested as potential donors of nucleotidyl moiety, only ATP, adenosine-5'-O-[3-thiotriphosphate], and acetyl-AMP were substrates, with relative velocities of 100, 62, and 80, respectively. The Km values for ATP, P3, and acetyl-AMP were 0.16, 4.7, and 1.8 mM, respectively. The synthesis of p4A could proceed in the absence of exogenous acetate but was stimulated twofold by acetate, with an apparent Km value of 0.065 mM. CoA did not participate in the synthesis of p4A (p5A) and inhibited the reaction (50% inhibitory concentration of 0.015 mM). At pH 6.3, which was optimum for formation of p4A (p5A), the rate of acetyl-CoA synthesis (1.84 mumol mg-1 min-1) was 245 times faster than the rate of synthesis of p4A measured in the presence of acetate. The known formation of p4A (p5A) in yeast sporulation and the role of acetate may therefore be related to acetyl-CoA synthetase.
2010-05-07T07:54:40Z
2010-05-07T07:54:40Z
1994-05
artículo
Journal of Bacteriology 176(10): 2986-2990 (1994)
0021-9193
http://hdl.handle.net/10261/24015
eng
http://jb.asm.org/cgi/content/short/176/10/2986
openAccess
American Society for Microbiology