title: NAD-dependent cross-linking of dinitrogenase reductase and dinitrogenase reductase ADP-ribosyltransferase from Rhodospirillum rubrum.
abstract: Chemical cross-linking of dinitrogenase reductase and dinitrogenase reductase ADP-ribosyltransferase (DRAT) from Rhodospirillum rubrum has been investigated with a cross-linking system utilizing two reagents, 1-ethyl-3-(3-dimethylaminopropyl)-carbodiimide and sulfo-N-hydroxysuccinimide. Cross-linking between dinitrogenase reductase and DRAT requires the presence of NAD, the cellular ADP-ribose donor, or a NAD analog containing an unmodified nicotinamide group, such as nicotinamide hypoxanthine dinucleotide. NADP, which will not replace NAD in the modification reaction, does support cross-linking between dinitrogenase reductase and DRAT. The DRAT-catalyzed ADP-ribosylation of dinitrogenase reductase is inhibited by sodium chloride, as is the cross-linking between dinitrogenase reductase and DRAT, suggesting that ionic interactions are required for the association of these two proteins. Cross-linking is specific for native, unmodified dinitrogenase reductase, in that both oxygen-denatured and ADP-ribosylated dinitrogenase reductase fail to form a cross-linked complex with DRAT. The ADP-bound and adenine nucleotide-free states of dinitrogenase reductase form cross-linked complexes with DRAT; however, cross-linking is inhibited when dinitrogenase reductase is in its ATP-bound state.
authors.affiliation: Department of Biochemistry, College of Agricultural and Life Sciences, University of Wisconsin-Madison 53706, USA.
authors.forename: S K
authors.initials: SK
authors.lastname: Grunwald
authors.forename: P W
authors.initials: PW
authors.lastname: Ludden
mesh_terms: D036002:ADP Ribose Transferases / Q000737:chemistry* / Q000187:drug effects / Q000378:metabolism; D000244:Adenosine Diphosphate / Q000494:pharmacology; D000246:Adenosine Diphosphate Ribose / Q000378:metabolism; D000255:Adenosine Triphosphate / Q000494:pharmacology; D000595:Amino Acid Sequence; D002384:Catalysis; D003432:Cross-Linking Reagents; D017037:Dinitrogenase Reductase / Q000737:chemistry* / Q000187:drug effects / Q000378:metabolism; D008969:Molecular Sequence Data; D009243:NAD / Q000502:physiology*; D012247:Rhodospirillum rubrum / Q000737:chemistry / Q000201:enzymology*; D012965:Sodium Chloride / Q000494:pharmacology
chemical_list: D003432:Cross-Linking Reagents; D017037:Dinitrogenase Reductase; D009243:NAD; D000246:Adenosine Diphosphate Ribose; D012965:Sodium Chloride; D000244:Adenosine Diphosphate; D000255:Adenosine Triphosphate; D036002:ADP Ribose Transferases; C057637:dinitrogenase reductase ADP-ribosyltransferase