4gr5

Publication Abstract from PubMed

The biosynthesis of non-ribosomally formed peptides (NRPs), which include important antibiotics such as vancomycin, requires the activation of amino acids through adenylate formation. The biosynthetic gene clusters of NRPs frequently contain genes for small, so-called MbtH-like proteins. Recently it was discovered that these MbtH-like proteins are required for some of the adenylation reactions in NRP biosynthesis, but the mechanism of their interaction with the adenylating enzymes has remained unknown. In this study, we determined the structure of SlgN1, a 3-methylaspartate adenylating enzyme involved in the biosynthesis of the hybrid polyketide/NRP antibiotic streptolydigin. SlgN1 contains an MbtH-like domain at its N-terminus, and our analysis defines the parameters required for an interaction between MbtH-like domains and an adenylating enzyme. Highly conserved tryptophan residues of the MbtH-like domain critically contribute to this interaction. W25 and W35 form a cleft on the surface of the MbtH-like domain, which accommodates the alanine side chain of A433 of the adenylating domain. Mutation of A433 to glutamate abolished the activity of SlgN1. Mutation of S23 of the MbtH-like domain to tyrosine resulted in strongly reduced activity. However, the activity of this S23Y mutant could be completely restored by addition of the intact MbtH-like protein CloY from another organism. This suggests that the interface found in the structure of SlgN1 is the genuine interface between MbtH-like proteins and adenylating enzymes.

Structural Basis of the Interaction of MbtH-Like Proteins, Putative Regulators of Non-Ribosomal Peptide Biosynthesis, with Adenylating Enzymes.,Herbst DA, Boll B, Zocher G, Stehle T, Heide L J Biol Chem. 2012 Nov 28. PMID:23192349^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.