Figure 1.

(A) Domain organization of the three subunits of yersiniabactin synthetase, including the seven-domain high molecular weight protein (HMWP)2 and nine-domain HMWP1 subunits. ArCP, aryl carrier protein; Cy, cyclization domain; A, adenylation domain; MT, methyltransferase; PCP, peptidyl carrier protein; KS, ketoacyl synthase; AT, acyltransferase; KR, ketoacyl reductase; ACP, acyl carrier protein; TE, thioesterase. (B) Postulated mechanism for Ybt translocation and release by C-terminal TE domain in HMWP1.