title: A disulfide linkage in a CCCH zinc finger motif of an Arabidopsis CPSF30 ortholog.
abstract: The Arabidopsis ortholog of the 30kDa subunit of the cleavage and polyadenylation factor (AtCPSF30) is an RNA binding endonuclease, and the endonuclease activity is inhibited by reducing agents. Here, we report the presence of a disulfide linkage in the endonuclease motif based on comparative mass spectrometry (MS) analysis of reduced and non-reduced but carbamidomethylated protein. This analysis reveals that this disulfide bond involves a CCCH zinc finger motif, one that is associated with the endonuclease activity of AtCPSF30. This finding raises the possibility that redox regulation of AtCPSF30 may occur through oxidation and reduction of the disulfide linkage.
authors.affiliation: Department of Chemistry, University of Cincinnati, Cincinnati, OH 45221-0172, USA. balasual@ucmail.uc.edu
authors.forename: Balasubrahmanyam
authors.initials: B
authors.lastname: Addepalli
authors.forename: Patrick A
authors.initials: PA
authors.lastname: Limbach
authors.forename: Arthur G
authors.initials: AG
authors.lastname: Hunt
mesh_terms: D000595:Amino Acid Sequence; D017360:Arabidopsis; D029681:Arabidopsis Proteins / Q000737:chemistry* / Q000378:metabolism; D055162:Biocatalysis; D002853:Chromatography, Liquid; D039223:Cleavage And Polyadenylation Specificity Factor / Q000737:chemistry* / Q000378:metabolism; D004220:Disulfides / Q000737:chemistry*; D004720:Endonucleases / Q000378:metabolism; D008969:Molecular Sequence Data; D017386:Sequence Homology, Amino Acid; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D053719:Tandem Mass Spectrometry; D016335:Zinc Fingers
chemical_list: D029681:Arabidopsis Proteins; C521936:CPSF30 protein, Arabidopsis; D039223:Cleavage And Polyadenylation Specificity Factor; D004220:Disulfides; D004720:Endonucleases