RRC ID 29154
Author Vandenberghe I, Kim JK, Devreese B, Hacisalihoglu A, Iwabuki H, Okajima T, Kuroda S, Adachi O, Jongejan JA, Duine JA, Tanizawa K, Van Beeumen J.
Title The covalent structure of the small subunit from Pseudomonas putida amine dehydrogenase reveals the presence of three novel types of internal cross-linkages, all involving cysteine in a thioether bond.
Journal J Biol Chem
Abstract Pseudomonas putida contains an amine dehydrogenase that is called a quinohemoprotein as it contains a quinone and two hemes c as redox active groups. Amino acid sequence analysis of the smallest (8.5 kDa), quinone-cofactor-bearing subunit of this heterotrimeric enzyme encountered difficulties in the interpretation of the results at several sites of the polypeptide chain. As this suggested posttranslational modifications of the subunit, the structural genes for this enzyme were determined and mass spectrometric de novo sequencing was applied to several peptides obtained by chemical or enzymatic cleavage. In agreement with the interpretation of the X-ray electronic densities in the diffraction data for the holoenzyme, our results show that the polypeptide of the small subunit contains four intrachain cross-linkages in which the sulfur atom of a cysteine residue is involved. Two of these cross-linkages occur with the beta-carbon atom of an aspartic acid, one with the gamma-carbon atom of a glutamic acid and the fourth with a tryptophanquinone residue, this adduct constituting the enzyme's quinone cofactor, CTQ. The thioether type bond in all four of these adducts has never been found in other proteins. CTQ is a novel cofactor in the series of the recently discovered quinone cofactors.
Volume 276(46)
Pages 42923-31
Published 2001-11-16
DOI 10.1074/jbc.M107164200
PII M107164200
PMID 11555656
MeSH Amino Acid Sequence Amino Acids / chemistry Cloning, Molecular Cross-Linking Reagents / pharmacology Cysteine / chemistry* Glutamic Acid / chemistry Heme / chemistry Indolequinones* Mass Spectrometry Models, Chemical Models, Genetic Molecular Sequence Data Open Reading Frames Oxidation-Reduction Oxidoreductases Acting on CH-NH Group Donors / chemistry* Oxidoreductases Acting on CH-NH Group Donors / genetics Oxidoreductases Acting on CH-NH Group Donors / metabolism Peptides / chemistry Protein Binding Protein Processing, Post-Translational Pseudomonas putida / enzymology* Quinones / chemistry Sequence Analysis, DNA Sequence Homology, Amino Acid Spectrometry, Mass, Electrospray Ionization Sulfides / chemistry* Tryptophan / analogs & derivatives* Tryptophan / chemistry X-Rays
IF 4.106
Times Cited 28
DNA material pUCP-Nde-QH-AmDH (RDB02849)