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How the MccB bacterial ancestor of ubiquitin E1 initiates biosynthesis of the microcin C7 antibiotic
- Source :
- The EMBO Journal. 28:1953-1964
- Publication Year :
- 2009
- Publisher :
- Wiley, 2009.
-
Abstract
- The 39-kDa Escherichia coli enzyme MccB catalyses a remarkable posttranslational modification of the MccA heptapeptide during the biosynthesis of microcin C7 (MccC7), a ‘Trojan horse' antibiotic. The approximately 260-residue C-terminal region of MccB is homologous to ubiquitin-like protein (UBL) activating enzyme (E1) adenylation domains. Accordingly, MccB-catalysed C-terminal MccA-acyl-adenylation is reminiscent of the E1-catalysed activation reaction. However, unlike E1 substrates, which are UBLs with a C-terminal di-glycine sequence, MccB's substrate, MccA, is a short peptide with an essential C-terminal Asn. Furthermore, after an intramolecular rearrangement of MccA-acyl-adenylate, MccB catalyses a second, unique reaction, producing a stable phosphoramidate-linked analogue of acyl-adenylated aspartic acid. We report six-crystal structures of MccB in apo, substrate-, intermediate-, and inhibitor-bound forms. Structural and kinetic analyses reveal a novel-peptide clamping mechanism for MccB binding to heptapeptide substrates and a dynamic-active site for catalysing dual adenosine triphosphate-consuming reactions. The results provide insight into how a distinctive member of the E1 superfamily carries out two-step activation for generating the peptidyl-antibiotic MccC7.
- Subjects :
- Models, Molecular
Protein Conformation
Ubiquitin-activating enzyme
Molecular Sequence Data
Sequence alignment
Ubiquitin-Activating Enzymes
Biology
Crystallography, X-Ray
Article
General Biochemistry, Genetics and Molecular Biology
Ligases
Protein structure
Bacteriocins
Catalytic Domain
Aspartic acid
Escherichia coli
Humans
Transferase
Amino Acid Sequence
Molecular Biology
Peptide sequence
Adenylylation
Aspartic Acid
General Immunology and Microbiology
Nucleotides
Escherichia coli Proteins
General Neuroscience
Microcin
Anti-Bacterial Agents
Biochemistry
Mutation
Peptides
Protein Processing, Post-Translational
Sequence Alignment
Protein Binding
Subjects
Details
- ISSN :
- 14602075 and 02614189
- Volume :
- 28
- Database :
- OpenAIRE
- Journal :
- The EMBO Journal
- Accession number :
- edsair.doi.dedup.....31103cb8f28a05b0aaccd7081e520111