This domain is found either on its own or in association with the tRNA synthetase class II core domain (Pfam:PF00587). It is involved in the tRNA editing of mis-charged tRNAs including Cys-tRNA(Pro), Cys-tRNA(Cys), Ala-tRNA(Pro)[2-5]. The structure of this domain shows a novel fold [1].

1: Crystal structure of YbaK protein from Haemophilus influenzae (HI1434) at 1.8 A resolution: functional implications. Zhang H, Huang K, Li Z, Banerjei L, Fisher KE, Grishin NV, Eisenstein E, Herzberg O; Proteins 2000;40:86-97. PMID:10813833

2: The bacterial YbaK protein is a Cys-tRNAPro and Cys-tRNA Cys deacylase. Ruan B, Soll D; J Biol Chem. 2005;280:25887-25891. PMID:15886196

3: Trans-editing of mischarged tRNAs. Ahel I, Korencic D, Ibba M, Soll D; Proc Natl Acad Sci U S A. 2003;100:15422-15427. PMID:14663147

4: Cys-tRNA(Pro) editing by Haemophilus influenzae YbaK via a novel synthetase.YbaK.tRNA ternary complex. An S, Musier-Forsyth K; J Biol Chem. 2005;280:34465-34472. PMID:16087664

5: Substrate-mediated fidelity mechanism ensures accurate decoding of proline codons. So BR, An S, Kumar S, Das M, Turner DA, Hadad CM, Musier-Forsyth K; J Biol Chem. 2011;286:31810-31820. PMID:21768119