{"uniprot":"Q96DC8","gene":"ECHDC3","name":"Enoyl-CoA hydratase domain-containing protein 3, mitochondrial","organism":"Homo sapiens (Human)","status":"dark","length":303,"sequence":"MAAVAVLRAFGASGPMCLRRGPWAQLPARFCSRDPAGAGRRESEPRPTSARQLDGIRNIVLSNPKKRNALSLAMLKSLQSDILHDADSNDLKVIIISAEGPVFSSGHDLKELTEEQGRDYHAEVFQTCSKVMMHIRNHPVPVIAMVNGLAAAAGCQLVASCDIAVASDKSSFATPGVNVGLFCSTPGVALARAVPRKVALEMLFTGEPISAQEALLHGLLSKVVPEAELQEETMRIARKIASLSRPVVSLGKATFYKQLPQDLGTAYYLTSQAMVDNLALRDGQEGITAFLQKRKPVWSHEPV","function_summary":"A soluble mitochondrial matrix protein built on a crotonase-like scaffold that assembles and stabilizes matrix enzyme complexes involved in acyl-CoA and related metabolic pathways. By oligomerizing and binding partner proteins, it likely tunes acyl-CoA flux and respiratory coupling in the matrix, thereby enhancing insulin-responsive cellular programs through improved mitochondrial metabolic signaling.","plain_language":"ECHDC3 has barely been studied. The model's best guess: A soluble mitochondrial matrix protein built on a crotonase-like scaffold that assembles and stabilizes matrix enzyme complexes involved in acyl-CoA and related metabolic pathways. By oligomerizing and binding partner proteins, it likely tunes acyl-CoA flux and respiratory coupling in the matrix, thereby enhancing insulin-responsive cellular programs through improved mitochondrial metabolic signaling.","uniprot_summary":"May be involved in metabolic processes.","go_terms":{"molecular_function":[{"id":"GO:0004300","label":"enoyl-CoA hydratase activity"},{"id":"GO:0005515","label":"protein binding"}],"biological_process":[{"id":"GO:1900078","label":"positive regulation of cellular response to insulin stimulus"}],"cellular_component":[{"id":"GO:0005759","label":"mitochondrial matrix"}]},"interpro":[{"id":"IPR029045","name":"ClpP/crotonase-like domain superfamily","type":"homologous_superfamily","start":45,"end":299},{"id":"IPR014748","name":"Enoyl-CoA hydratase, C-terminal","type":"homologous_superfamily","start":244,"end":300},{"id":"IPR001753","name":"Enoyl-CoA hydratase/isomerase-like domain","type":"domain","start":54,"end":299},{"id":"IPR052377","name":"Mitochondrial enoyl-CoA hydratase domain-containing protein","type":"family","start":5,"end":301}],"reasoning":"I begin with the InterPro architecture. The core of the protein is defined by IPR001753 (Enoyl-CoA hydratase/isomerase-like domain, residues 54–299), embedded within IPR029045 (ClpP/crotonase-like domain superfamily, residues 45–299). This crotonase/enoyl-CoA hydratase fold forms a soluble oligomeric barrel that typically binds acyl-CoA substrates and organizes catalytic acid/base residues for hydration/dehydration chemistry. The C-terminal region is reinforced by IPR014748 (Enoyl-CoA hydratase, C-terminal homologous superfamily, residues 244–300), which stabilizes the active-site architecture and oligomeric assembly characteristic of this enzyme-like scaffold. The entire polypeptide is classified by IPR052377 (Mitochondrial enoyl-CoA hydratase domain-containing protein family, residues 5–301), anchoring the fold and oligomerization state to a mitochondrial context. The ordered layout—an N-terminal mitochondrial specialization followed by a complete crotonase-like core and a consolidating C-terminal segment—creates a soluble, matrix-facing assembly platform rather than a membrane anchor.\n\nThis crotonase-like architecture causes two immediate functional consequences. First, it supports GO:0004300 enoyl-CoA hydratase activity as the intrinsic chemistry of the fold, even if catalysis is tuned or muted in some family members. Second, the extensive oligomeric surface and conserved grooves favor multivalent contacts with other matrix proteins, consistent with GO:0005515 protein binding. In mitochondria, such hydratase-like scaffolds often act as pseudoenzymes that recruit and stabilize components of metabolic assemblies.\n\nFrom molecular function to process, a hydratase-like scaffold in the mitochondrial matrix naturally feeds into pathways that couple fatty acid and amino acid catabolism to cellular energy signaling. By organizing matrix enzyme assemblies and tuning acyl-CoA flux, the protein can modulate the production of acetyl-CoA and downstream respiratory outputs that influence insulin responsiveness. This mechanistic coupling provides a causal route to GO:1900078 positive regulation of cellular response to insulin stimulus: enhanced mitochondrial efficiency and signaling can amplify insulin-responsive pathways.\n\nThe absence of transmembrane segments and the presence of a soluble crotonase-like core argue for a matrix-localized soluble protein. The mitochondrial specialization of IPR052377 and the soluble hydratase fold together place the protein in GO:0005759 mitochondrial matrix. This is concordant with a matrix-resident role where it can assemble and regulate metabolic complexes.\n\nMechanistically, I hypothesize that the protein forms an oligomeric platform that binds acyl-CoA–processing enzymes and respiratory assembly factors. By transiently engaging enoyl-CoA hydratase/isomerase-like partners and matrix chaperones, it stabilizes β-oxidation and related pathways and coordinates with signaling nodes that report mitochondrial status to cytosolic insulin-response circuits. Likely interaction partners include matrix enzyme assemblies such as acyl-CoA dehydrogenase complexes and the mitochondrial ribosome, which together create a hub that couples metabolism to signaling.","category":"dark","control_evaluation":null,"validation_plan":null,"structure":{"source":"AlphaFold DB","pdb":"/structures/AF-Q96DC8.pdb","alphafold":"https://alphafold.ebi.ac.uk/entry/Q96DC8"},"links":{"uniprot":"https://www.uniprot.org/uniprotkb/Q96DC8/entry","atlas":"/p/Q96DC8"},"provenance":{"model":"BioReason-Pro (ESM3 esm3-sm-open-v1)","source_list":"Pharos Tdark","note":"AI prediction, not experimentally verified"}}