Rapid protein sequencing by tandem mass spectrometry and cDNA cloning of p20-CGGBP. A novel protein that binds to the unstable triplet repeat 5'-d(CGG)n-3' in the human FMR1 gene.
The autonomous expansion of the unstable 5'-d(CGG)n-3' repeat in the 5'-untranslated region of the human FMR1 gene leads to the fragile X syndrome, one of the most frequent causes of mental retardation in human males. We have recently described the isolation of a protein p20-CGGBP that binds sequence-specifically to the double-stranded trinucleotide repeat 5'-d(CGG)-3' (Deissler, H., Behn-Krappa, A., and Doerfler, W. (1996) J. Biol. Chem. 271, 4327-4334). We demonstrate now that the p20-CGGBP can also bind to an interrupted repeat sequence. Peptide sequence tags of p20-CGGBP obtained by nanoelectrospray mass spectrometry were screened against an expressed sequence tag data base, retrieving a clone that contained the full-length coding sequence for p20-CGGBP. A bacterially expressed fusion protein p20-CGGBP-6xHis exhibits a binding pattern to the double-stranded 5'-d(CGG)n-3' repeat similar to that of the authentic p20-CGGBP. This novel protein lacks any overall homology to other known proteins but carries a putative nuclear localization signal. The p20-CGGBP gene is conserved among mammals but shows no homology to non-vertebrate species. The gene encoding the sequence for the new protein has been mapped to human chromosome 3.
Deissler
H
H
Institut für Genetik, Universität zu Köln, D-50931 Köln, Federal Republic of Germany.
Wilm
M
M
Genç
B
B
Schmitz
B
B
Ternes
T
T
Naumann
F
F
Mann
M
M
Doerfler
W
W
D000595:Amino Acid Sequence; D001665:Binding Sites; D002874:Chromosome Mapping; D004247:DNA / Q000378:metabolism; D018076:DNA, Complementary / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D051860:Fragile X Messenger Ribonucleoprotein 1; D006367:HeLa Cells; D006801:Humans; D013058:Mass Spectrometry / Q000379:methods*; D008969:Molecular Sequence Data; D009419:Nerve Tissue Proteins / Q000235:genetics*; D016366:Open Reading Frames; D010449:Peptide Mapping / Q000379:methods*; D011401:Promoter Regions, Genetic; D011485:Protein Binding; D016601:RNA-Binding Proteins / Q000235:genetics*; D018911:Trinucleotide Repeats
D004247:DNA; D018076:DNA, Complementary; D004268:DNA-Binding Proteins; D051860:Fragile X Messenger Ribonucleoprotein 1; D009419:Nerve Tissue Proteins; D016601:RNA-Binding Proteins; C106905:CGGBP1 protein, human; C497683:FMR1 protein, human