{"entry": {"accession": "MF7000210", "general": {"name": "Chorismate mutase (Mycobacterium tuberculosis)", "pdb_id": "5mpv", "exp_method": "X-ray", "resolution": "1.49", "assembly": "Homodimer", "source_organism": "Mycobacterium tuberculosis", "publication": {"pmid": "33453995", "authors": "Fahrig-Kamarauskait J, W\u00fcrth-Roderer K, Thorbj\u00f8rnsrud HV, Mailand S, Krengel U, Kast P", "title": "Evolving the naturally compromised chorismate mutase from Mycobacterium tuberculosis to top performance.", "journal": "J. Biol. Chem.", "year": "2020", "issue": "51", "volume": "295", "pages": "17514-17534", "abstract": "Chorismate mutase (CM), an essential enzyme at the branch-point of the shikimate pathway, is required for the biosynthesis of phenylalanine and tyrosine in bacteria, archaea, plants, and fungi. MtCM, the CM from Mycobacterium tuberculosis, has less than 1% of the catalytic efficiency of a typical natural CM and requires complex formation with 3-deoxy-d-arabino-heptulosonate 7-phosphate synthase for high activity. To explore the full potential of MtCM for catalyzing its native reaction, we applied diverse iterative cycles of mutagenesis and selection, thereby raising k<sub>cat</sub>/K<sub>m</sub> 270-fold to 5 \u00d7 10<sub>5</sub>m<sub>-1</sub>s<sub>-1</sub>, which is even higher than for the complex. Moreover, the evolutionarily optimized autonomous MtCM, which had 11 of its 90 amino acids exchanged, was stabilized compared with its progenitor, as indicated by a 9 \u00b0C increase in melting temperature. The 1.5 \u00c5 crystal structure of the top-evolved MtCM variant reveals the molecular underpinnings of this activity boost. Some acquired residues (e.g. Pro<sub>52</sub> and Asp<sub>55</sub>) are conserved in naturally efficient CMs, but most of them lie beyond the active site. Our evolutionary trajectories reached a plateau at the level of the best natural enzymes, suggesting that we have exhausted the potential of MtCM. Taken together, these findings show that the scaffold of MtCM, which naturally evolved for mediocrity to enable inter-enzyme allosteric regulation of the shikimate pathway, is inherently capable of high activity."}}, "function": {"molecular_function": {"go": {"accession": "GO:0004106", "name": "chorismate mutase activity"}}, "cellular_component": {"go": [{"accession": "GO:0005737", "name": "cytoplasm"}, {"accession": "GO:0005886", "name": "plasma membrane"}]}, "biological_process": {"go": [{"accession": "GO:0008652", "name": "amino acid biosynthetic process"}, {"accession": "GO:0009095", "name": "aromatic amino acid family biosynthetic process, prephenate pathway"}, {"accession": "GO:0046417", "name": "chorismate metabolic process"}, {"accession": "GO:0009697", "name": "salicylic acid biosynthetic process"}]}}, "macromolecules": {"general": {"nr_of_chains": "2", "nr_of_unique_protein_segments": "1", "class": "Homooligomeric enzymes", "subclass": "Homodimeric enzymes", "note": "All chains according to the most probable oligomerization state stored in PDBe were considered."}, "chain": [{"id": "D", "name": "Intracellular chorismate mutase", "source_organism": "Mycobacterium tuberculosis", "uniprot": {"id": "P9WIC1", "start": "26", "end": "93", "coverage": "64%", "sequence": "MRPEPPHHENAELAAMNLEMLESQPVPEIDTLREEIDRLDAEILALVKRRAEVSKAIGKARMASGGTRLVHSREMKVIERYSELGPDGKDLAILLLRLGRGRLGH", "length": "105"}, "regions": {"region": [{"region_type": "secondary structure", "region_name": "helix", "region_start": "11", "region_end": "13"}, {"region_type": "secondary structure", "region_name": "helix", "region_start": "14", "region_end": "49"}, {"region_type": "secondary structure", "region_name": "helix", "region_start": "55", "region_end": "67"}, {"region_type": "secondary structure", "region_name": "helix", "region_start": "70", "region_end": "84"}, {"region_type": "pfam", "region_id": "PF01817", "region_name": "Chorismate mutase type II", "region_start": "32", "region_end": "88"}]}}, {"id": "D-2", "name": "Intracellular chorismate mutase", "source_organism": "Mycobacterium tuberculosis", "uniprot": {"id": "P9WIC1", "start": "26", "end": "93", "coverage": "64%", "sequence": "MRPEPPHHENAELAAMNLEMLESQPVPEIDTLREEIDRLDAEILALVKRRAEVSKAIGKARMASGGTRLVHSREMKVIERYSELGPDGKDLAILLLRLGRGRLGH", "length": "105"}, "regions": {"region": {"region_type": "pfam", "region_id": "PF01817", "region_name": "Chorismate mutase type II", "region_start": "32", "region_end": "88"}}}]}, "evidence": {"evidence_level": "Indirect evidence", "evidence_coverage": "The full structure participates in mutual synergistic folding.", "sequence_domain": "Chorismate mutase type II", "complex_evidence": "The enzyme is an intertwined dimer of three helices with connecting loops. The N-terminal helices of the two monomers twine together to form an anti-parallel coiled-coil with a hydrophobic interaction surface. The loop between the first and second helices is disordered (PMID:16914555).", "chain_evidence": [{"chain_id": "D", "support": "N/A"}, {"chain_id": "D-2", "support": "N/A"}]}, "related_structures": {"id": ["MF7000162", "MF7000212", "MF7000163", "MF7000211", "MF7000164", "MF7000165", "MF7000209", "MF7000210"]}}}