title: (1)H, (13)C, and (15)N resonance assignments and secondary structure information for Methylobacterium extorquens PqqD and the complex of PqqD with PqqA.
abstract: The ribosomally synthesized and post-translationally modified peptide (RiPP), pyrroloquinoline quinone (PQQ), is a dehydrogenase cofactor synthesized by, but not exclusively used by, certain prokaryotes. RiPPs represent a rapidly expanding and diverse class of natural products-many of which have therapeutic potential-and the biosynthetic pathways for these are gaining attention. Five gene products from the pqq operon (PqqA, PqqB, PqqC, PqqD, and PqqE) are essential for PQQ biosynthesis. The substrate is the peptide PqqA, which is presented to the radical SAM enzyme PqqE by the small protein PqqD. PqqA is unstructured in solution, and only binds to PqqE when in complex with PqqD. PqqD is a member of a growing family of RiPP chaperone proteins (or domains in most cases) that present their associated peptide substrates to the initial RiPP biosynthesis enzymes. An X-ray crystal structure exists for dimeric Xanthomonas campestris PqqD (PDB ID: 3G2B), but PqqD is now known to act as a monomer under physiological conditions. In this study, the PqqD truncation from naturally fused Methylobacterium extorquens (Mex) PqqCD was overexpressed in Escherichia coli and MexPqqA was chemically synthesized. Solution NMR (1)H-,(15)N-HSQC chemical shift studies have identified the PqqD residues involved in binding PqqA, and (1)H, (13)C, and (15)N peak assignments for PqqD alone and for PqqD bound to PqqA are reported herein.
authors.affiliation: Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Twin Cities, Saint Paul, MN, 55108, USA.
authors.forename: Robert L
authors.initials: RL
authors.lastname: Evans
authors.affiliation: Department of Chemistry, University of California, Berkeley, Berkeley, CA, 94720, USA.|Department of Chemistry and Biochemistry, University of Denver, Denver, CO, 80208, USA.
authors.forename: John A
authors.initials: JA
authors.lastname: Latham
authors.affiliation: Department of Chemistry, University of California, Berkeley, Berkeley, CA, 94720, USA.|Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA, 94720, USA.
authors.forename: Judith P
authors.initials: JP
authors.lastname: Klinman
authors.affiliation: Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Twin Cities, Saint Paul, MN, 55108, USA. Wilmo004@umn.edu.
authors.forename: Carrie M
authors.initials: CM
authors.lastname: Wilmot
authors.affiliation: Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Twin Cities, Saint Paul, MN, 55108, USA.|Minnesota NMR Center, University of Minnesota, Twin Cities, Minneapolis, MN, 55455, USA.
authors.forename: Youlin
authors.initials: Y
authors.lastname: Xia
mesh_terms: D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000737:chemistry* / Q000378:metabolism*; D020601:Methylobacterium extorquens; D019906:Nuclear Magnetic Resonance, Biomolecular; D045542:PQQ Cofactor / Q000378:metabolism*; D017433:Protein Structure, Secondary
chemical_list: D001426:Bacterial Proteins; D045542:PQQ Cofactor
keywords: NMR resonance assignments; PQQ; PqqA; PqqD; Pyrroloquinoline quinone biosynthesis; RiPP