6OM4
The structure of Microcin C7 biosynthetic enzyme MccB in complex with N-formylated MccA
Summary for 6OM4
| Entry DOI | 10.2210/pdb6om4/pdb |
| Descriptor | MccB protein, Microcin C7, ZINC ION, ... (7 entities in total) |
| Functional Keywords | microcin c7, phosphoramidate, trojan horse antibiotic, biosynthetic protein |
| Biological source | Escherichia coli More |
| Total number of polymer chains | 4 |
| Total formula weight | 80564.36 |
| Authors | Dong, S.-H.,Nair, S.K. (deposition date: 2019-04-18, release date: 2019-05-22, Last modification date: 2024-10-23) |
| Primary citation | Dong, S.H.,Kulikovsky, A.,Zukher, I.,Estrada, P.,Dubiley, S.,Severinov, K.,Nair, S.K. Biosynthesis of the RiPP trojan horse nucleotide antibiotic microcin C is directed by theN-formyl of the peptide precursor. Chem Sci, 10:2391-2395, 2019 Cited by PubMed Abstract: Microcin C7 (McC) is a peptide antibiotic modified by a linkage of the terminal isoAsn amide to AMP a phosphoramidate bond. Post-translational modification on this ribosomally produced heptapeptide precursor is carried out by MccB, which consumes two equivalents of ATP to generate the N-P linkage. We demonstrate that MccB only efficiently processes the precursor heptapeptide that retains the -formylated initiator Met (fMet). Binding studies and kinetic measurements evidence the role of the -formyl moiety. Structural data show that the -formyl peptide binding results in an ordering of residues in the MccB "crossover loop", which dictates specificity in homologous ubiquitin activating enzymes. The -formyl peptide exhibits substrate inhibition, and cannot be displaced from MccB by the desformyl counterpart. Such substrate inhibition may be a strategy to avert unwanted McC buildup and avert toxicity in the cytoplasm of producing organisms. PubMed: 30881667DOI: 10.1039/c8sc03173h PDB entries with the same primary citation |
| Experimental method | X-RAY DIFFRACTION (1.7 Å) |
Structure validation
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