FIGURE 1.

Complementation of the E. coli ΔselA mutant with phosphoseryl-tRNA^Sec kinase (PSTK) and SepCysS. The in vivo activities of M. jannaschii wild-type and mutant (K234A, C64A, C67A, C272A, C209A, and C113A) SepCysS converting Sep-tRNA^Sec to Cys-tRNA^Sec were tested by their ability to restore formate dehydrogenase H activity in the E. coli ΔselA mutant. The complementation was observed by formation of purple colonies resulted from reduction of benzyl viologen with formate. The complementation required co-expression of phosphoseryl-tRNA^Sec kinase, which converts Ser-tRNA^Sec to Sep-tRNA^Sec.