title: A unique cis-3-hydroxy-l-proline dehydratase in the enolase superfamily.
abstract: The genome of Labrenzia aggregata IAM 12614 encodes an uncharacterized member of the muconate lactonizing enzyme (MLE) subgroup of the enolase superfamily (UniProt ID A0NXQ8 ). The gene encoding A0NXQ8 is located between genes that encode members of the proline racemase superfamily, 4R-hydroxyproline 2-epimerase (UniProt ID A0NXQ7 ; 4HypE) and trans-3-hydroxy-l-proline dehydratase (UniProt ID A0NXQ9 ; t3LHypD). A0NXQ8 was screened with a library of proline analogues; two reactions were observed with cis-3-hydroxy-l-proline (c3LHyp), competing 2-epimerization to trans-3-hydroxy-d-proline (1,1-proton transfer) and dehydration to Δ(1)-pyrroline-2-carboxylate (β-elimination; c3LHyp dehydratase), with eventual total dehydration. The genome context encoding A0NXQ8 both (1) confirms its novel c3LHyp dehydratase function and (2) provides evidence for metabolic pathways that allow L. aggregata to utilize several isomeric 3- and 4-hydroxyprolines as sole carbon sources.
authors.affiliation: Departments of Biochemistry and Chemistry and ‡Institute for Genomic Biology, University of Illinois at Urbana-Champaign , Urbana, Illinois 61801, United States.
authors.forename: Xinshuai
authors.initials: X
authors.lastname: Zhang
authors.forename: Ritesh
authors.initials: R
authors.lastname: Kumar
authors.forename: Matthew W
authors.initials: MW
authors.lastname: Vetting
authors.forename: Suwen
authors.initials: S
authors.lastname: Zhao
authors.forename: Matthew P
authors.initials: MP
authors.lastname: Jacobson
authors.forename: Steven C
authors.initials: SC
authors.lastname: Almo
authors.forename: John A
authors.initials: JA
authors.lastname: Gerlt
mesh_terms: D000591:Amino Acid Isomerases / Q000235:genetics / Q000378:metabolism; D016680:Genome, Bacterial; D006836:Hydro-Lyases / Q000235:genetics / Q000378:metabolism*; D006909:Hydroxyproline / Q000737:chemistry / Q000378:metabolism*; D008958:Models, Molecular; D041902:Rhodobacteraceae / Q000201:enzymology* / Q000235:genetics / Q000378:metabolism; D013379:Substrate Specificity
chemical_list: D006836:Hydro-Lyases; D000591:Amino Acid Isomerases; C021420:hydroxyproline epimerase; D006909:Hydroxyproline