{"database":"biostudies-literature","file_versions":[],"scores":null,"additional":{"omics_type":["Unknown"],"submitter":["Gatreddi S"],"funding":["NIGMS NIH HHS"],"pubmed_abstract":["The nickel pincer nucleotide (NPN) cofactor catalyzes the racemization/epimerization of α-hydroxy acids in enzymes of the LarA family. The established proton-coupled hydride transfer mechanism requires two catalytic histidine residues that alternately act as general acids and general bases. Notably, however, a fraction of LarA homologs (LarAHs) lack one of the active site histidine residues, replacing it with an asparaginyl side chain that cannot participate in acid/base catalysis. Here, we investigated two such LarAHs and solved their cryo-electron microscopic structures with and without loaded NPN cofactor, respectively. The structures revealed a consistent octameric assembly that is unprecedented in the LarA family and unveiled a new set of active site residues that likely recognize and"],"journal":["bioRxiv : the preprint server for biology"],"pagination":["2025.08.19.671153"],"full_dataset_link":["https://www.ebi.ac.uk/biostudies/studies/S-EPMC12393405"],"repository":["biostudies-literature"],"pubmed_title":["Structures of two LarA-like nickel-pincer nucleotide cofactor-utilizing enzymes with a single catalytic histidine residue."],"pmcid":["PMC12393405"],"funding_grant_id":["R35 GM140931","R01 GM128959","R35 GM140803"],"pubmed_authors":["Desguin B","Sui D","Hu J","Wang T","Urdiain-Arraiza J","Hausinger RP","Gatreddi S","Parent KN","Subramanian S"],"additional_accession":[]},"is_claimable":false,"name":"Structures of two LarA-like nickel-pincer nucleotide cofactor-utilizing enzymes with a single catalytic histidine residue.","description":"The nickel pincer nucleotide (NPN) cofactor catalyzes the racemization/epimerization of α-hydroxy acids in enzymes of the LarA family. The established proton-coupled hydride transfer mechanism requires two catalytic histidine residues that alternately act as general acids and general bases. Notably, however, a fraction of LarA homologs (LarAHs) lack one of the active site histidine residues, replacing it with an asparaginyl side chain that cannot participate in acid/base catalysis. Here, we investigated two such LarAHs and solved their cryo-electron microscopic structures with and without loaded NPN cofactor, respectively. The structures revealed a consistent octameric assembly that is unprecedented in the LarA family and unveiled a new set of active site residues that likely recognize and","dates":{"release":"2025-01-01T00:00:00Z","publication":"2025 Aug","modification":"2026-05-29T03:08:37.631Z","creation":"2026-05-29T03:05:38.807Z"},"accession":"S-EPMC12393405","cross_references":{"pubmed":["40894700"],"doi":["10.1101/2025.08.19.671153"]}}