title: Comparison of native and mutant proteins provides a sequence-specific assignment of the cysteinyl ligand proton NMR resonances in the 2[Fe4S4] ferredoxin from Clostridium pasteurianum.
abstract: A sequence-specific assignment is presented for the eight low-field paramagnetically shifted cysteinyl ligand proton NMR resonances in the 2[Fe4S4] ferredoxin from Clostridium pasteurianum. The assignment is based upon comparison of chemical shifts in 1D and 2D NMR spectra of native oxidized protein and those of three mutants. The mutant proteins G12A and G41A were designed to produce minor local structural changes (hence small chemical shift perturbations) in either cluster I (glycine 12 to alanine) or in cluster II (glycine 41 to alanine). Observed chemical shift changes in spectra of the double mutant G12,41A support the interpretation. The comparison is aided by structural models derived from the crystal structure of the related ferredoxin from Peptococcus aerogenes. Each of the eight low-field resonances is assigned to a beta-proton from a different cysteinyl ligand, and so connectivities established from previous TOCSY and HMQC data allow assignment of all 24 cysteinyl ligand protons.
authors.affiliation: Department of Chemistry, La Trobe University, Bundoora, Victoria, Australia.
authors.forename: S D
authors.initials: SD
authors.lastname: Scrofani
authors.forename: P S
authors.initials: PS
authors.lastname: Brereton
authors.forename: A M
authors.initials: AM
authors.lastname: Hamer
authors.forename: M J
authors.initials: MJ
authors.lastname: Lavery
authors.forename: S G
authors.initials: SG
authors.lastname: McDowall
authors.forename: G A
authors.initials: GA
authors.lastname: Vincent
authors.forename: R T
authors.initials: RT
authors.lastname: Brownlee
authors.forename: N J
authors.initials: NJ
authors.lastname: Hoogenraad
authors.forename: M
authors.initials: M
authors.lastname: Sadek
authors.forename: A G
authors.initials: AG
authors.lastname: Wedd
mesh_terms: D000595:Amino Acid Sequence; D001483:Base Sequence; D003013:Clostridium / Q000737:chemistry*; D003545:Cysteine / Q000737:chemistry; D017931:DNA Primers / Q000737:chemistry; D005288:Ferredoxins / Q000737:chemistry*; D007506:Iron-Sulfur Proteins / Q000737:chemistry; D008024:Ligands; D009682:Magnetic Resonance Spectroscopy; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D011994:Recombinant Proteins; D013329:Structure-Activity Relationship
chemical_list: D017931:DNA Primers; D005288:Ferredoxins; D007506:Iron-Sulfur Proteins; D008024:Ligands; D011994:Recombinant Proteins; D003545:Cysteine