Cloning and characterization of the cDNA encoding human adenylosuccinate synthetase.
Adenylosuccinate synthetase (AS) catalyzes the first committed step in the conversion of IMP to AMP. A cDNA was isolated from a human liver library which encodes a protein of 455 amino acids (M(r) of 49,925). Alignments of human, mouse, Dictyostelium discoideum and E. coli AS sequences identify a number of invariant residues which are likely to be important for structure and/or catalysis. The human AS sequence was also 19% identical to the human urea cycle enzyme, argininosuccinate synthetase (ASS), which catalyzes a chemically similar reaction. Both human liver and HeLa AS mRNA showed signals of 2.3 and 2.8 kb. An unmodified N-terminus is required for function of the human AS enzyme in E. coli mutants lacking the bacterial enzyme. The human cDNA provides a means to assess the possible role of AS abnormalities in unclassified, idiopathic cases of gout.
Powell
S M
SM
Department of Biochemistry, Purdue University, West Lafayette, IN 49707.
Zalkin
H
H
Dixon
J E
JE
D000265:Adenylosuccinate Synthase / Q000235:genetics*; D000595:Amino Acid Sequence; D001483:Base Sequence; D015152:Blotting, Northern; D003001:Cloning, Molecular; D004247:DNA / Q000235:genetics*; D006367:HeLa Cells; D006801:Humans; D008099:Liver / Q000201:enzymology; D008969:Molecular Sequence Data; D012333:RNA, Messenger / Q000235:genetics; D016415:Sequence Alignment
D012333:RNA, Messenger; D004247:DNA; D000265:Adenylosuccinate Synthase