title: An electrospray ionisation mass spectrometry (ESI-MS) study to probe the metal ion binding site in the DNA binding domain of the yeast transcriptional activator GAL4.
abstract: Electrospray ionisation mass spectrometry (ESI-MS) is used to detect metal ions and their stoichiometry of binding in the DNA binding domain of GAL4. In this analysis, the mass spectra of the apo- and metallo-proteins differ by both mass and charge, precluding the possibility of random adduct formation. Deuterium exchange NMR experiments of Zn(II)-GAL4(7-49) indicate that the binuclear metal ion structure, which is shown to have a net negative charge of -2, is the recipient of several hydrogen bonds, notably from the main-chain amide protons of the ligating cysteine residues, indicating the charge is stabilised in this manner.
authors.affiliation: Cambridge Centre for Molecular Recognition, Department of Biochemistry, University of Cambridge, UK. p-gadhav@nimr.mrc.ac.uk
authors.forename: P L
authors.initials: PL
authors.lastname: Gadhavi
mesh_terms: D000595:Amino Acid Sequence; D001665:Binding Sites; D002104:Cadmium / Q000378:metabolism*; D002413:Cations, Divalent / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000737:chemistry* / Q000378:metabolism; D005656:Fungal Proteins / Q000737:chemistry* / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D013058:Mass Spectrometry; D008670:Metals / Q000378:metabolism; D008969:Molecular Sequence Data; D012441:Saccharomyces cerevisiae / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins; D012680:Sensitivity and Specificity; D015534:Trans-Activators / Q000378:metabolism; D014157:Transcription Factors / Q000737:chemistry* / Q000378:metabolism; D015032:Zinc / Q000378:metabolism*
chemical_list: D002413:Cations, Divalent; D004268:DNA-Binding Proteins; D005656:Fungal Proteins; C052130:GAL4 protein, S cerevisiae; D008670:Metals; D029701:Saccharomyces cerevisiae Proteins; D015534:Trans-Activators; D014157:Transcription Factors; D002104:Cadmium; D015032:Zinc