Peptide sequencing identifies MSS1, a modulator of HIV Tat-mediated transactivation, as subunit 7 of the 26 S protease.
Subunit 7 is an integral component of the human erythrocyte 26 S protease. Peptide sequence analysis reveals that 22 amino acids from the N-terminus of subunit 7 correspond exactly to the N-terminus of MSS1, a modulator of HIV gene expression. Additional internal peptides from subunit 7 obtained by CNBr cleavage also match 100% with the deduced amino acid sequence of MSS1. Based on the fact that directly sequenced peptides from subunit 7 are identical to more than 12% of the hypothetical translation product of MSS1, and the fact that the molecular weight of subunit 7 (49 kDa) corresponds to the predicted molecular weight of MSS1 (48,633 Da), we conclude that subunit 7 is MSS1.
Department of Biochemistry, University of Utah, School of Medicine, Salt Lake City 84132.
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D000074183:ATPases Associated with Diverse Cellular Activities; D000595:Amino Acid Sequence; D002851:Chromatography, High Pressure Liquid; D004268:DNA-Binding Proteins / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D004591:Electrophoresis, Polyacrylamide Gel; D015967:Gene Expression Regulation, Viral; D015696:Gene Products, tat / Q000378:metabolism*; D006678:HIV / Q000235:genetics* / Q000378:metabolism*; D006801:Humans; D046911:Macromolecular Substances; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000302:isolation & purification; D010447:Peptide Hydrolases / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D046988:Proteasome Endopeptidase Complex; D017386:Sequence Homology, Amino Acid; D015533:Transcriptional Activation; D054322:tat Gene Products, Human Immunodeficiency Virus
D004268:DNA-Binding Proteins; D015696:Gene Products, tat; D046911:Macromolecular Substances; D010446:Peptide Fragments; D054322:tat Gene Products, Human Immunodeficiency Virus; C075363:PSMC2 protein, human; D010447:Peptide Hydrolases; D046988:Proteasome Endopeptidase Complex; C061553:ATP dependent 26S protease; D000074183:ATPases Associated with Diverse Cellular Activities