2.7.7.B5 D189A mutation eliminates in vivo function of the enzyme 691789 2.7.7.B5 K321M mutation eliminates in vivo function of the enzyme 691789 2.7.7.B5 additional information construction of two truncated forms of ThiI containing the N-terminal domain including NFLD and THUMP, and the C-terminal domain including the PP-loop and RLD domains, respectively. The N-domain can bind with both tRNAPhe and TPHE39A and recognizes the acceptor-stem region, whereas the C-domain cannot. The C-domain also affects RNA binding by its enthalpically favorable, but entropically unfavorable, contribution. The C-domain induces a conformation change in tRNAPhe 710548 2.7.7.B5 C207S using a complementation assay it is shown that mutant is required for 4-thiouridine synthesis but not for thiazole synthesis 725262 2.7.7.B5 C344S using a complementation assay it is shown that mutant is required for 4-thiouridine synthesis but not for thiazole synthesis 725262 2.7.7.B5 C456S using a complementation assay it is shown that mutant is required for 4-thiouridine synthesis and for thiazole synthesis 725262 2.7.7.B5 D189A using a complementation assay it is shown that mutant is required for 4-thiouridine synthesis but not for thiazole synthesis 725262 2.7.7.B5 K321M using a complementation assay it is shown that mutant is required for 4-thiouridine synthesis but not for thiazole synthesis 725262