6.3.4.2 | -999 |
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a structure-activity study using a variety of GTP and guanosine analogues reveals that only a few GTP analogues are capable of activating Gln-dependent CTP formation to varying degrees: GTP > 6-thio-GTP > ITP> guanosine 5'-tetraphosphate > O-methyl-GTP > 2'-deoxy-GTP. No activation is observed with guanosine, GMP, GDP, 2',3'-dideoxy-GTP, acycloguanosine, and acycloguanosine monophosphate indicating that the 5'-triphosphate, 2'-OH, and 3'-OH are required for full activation. The 2-NH2 group is important in binding recognition while substituents at the 6-position are important in activation. |
674909 |