FUNCTION : IMP IS THE RATE LIMITING ENZYME IN THE DE NOVO SYNTHESIS OF GUANINE NUCLEOTIDES AND THEREFORE IS INVOLVED IN THE REGULATION OF CELL GROWTH. IT MAY ALSO HAVE A ROLE IN THE DEVELOPMENT OF MALIGNANCY AND THE GROWTH PROGRESSION OF SOME TUMORS. CATALYTIC ACTIVITY : Inosine 5'-phosphate + NAD ++ H 2O = xanthosine 5'-phosphate + NADH. PATHWAY : FIRST REACTION UNIQUE TO GMP BIOSYNTHESIS. SUBUNIT : Homotetramer. TISSUE SPECIFICITY : IMP TYPE I IS THE MAIN SPECIES IN NORMAL LEUKOCYTES AND TYPE II PREDOMINATES OVER TYPE I IN THE TUMOR. PTM : The N-terminus is blocked. SIMILARITY : BELONGS TO THE IMPDH/GMPR FAMILY. SIMILARITY : Contains 2 CBS domains. |
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27-Feb-03
Last Update 13-Mar-03