title: Early region 1B of adenovirus 2 encodes two coterminal proteins of 495 and 155 amino acid residues.
abstract: Partial sequence analysis of tryptic peptides has identified the E1B-495R (E1b-57K) (early transcription region 1B of 495 amino acid residues, with an approximate molecular weight of 57,000) protein of adenovirus 2 as encoded by the 495 amino acid open reading frame located in the adenovirus 2 DNA sequence between nucleotides 2016 and 3500. Additional proteins of 16,000 Mr and 18,000 Mr that are related to the E1B-495R protein were identified by cell-free translation of hybridization-selected mRNA. Analysis of [35S]methionine-containing amino terminal tryptic peptides by thin-layer chromatography showed that the E1B-495R, E1B-18K, and E1B-16K proteins all begin at the same initiation codon. The E1B-495R protein from 293 cells also has the same initial tryptic peptide, acetyl-methionyl-glutamyl-arginine. Sequence analysis of E1B-18K tryptic peptides indicated that this protein also has the same carboxy terminus as the E1B-495R protein and that it is derived from an mRNA that is spliced to remove sequences between nucleotides 2250 and 3269, resulting in a protein product of 155 amino acid residues. Analysis of E1B-16K tryptic peptides has not yet revealed the carboxy terminal structure of this protein. Both the E1B-495R and the E1B-155R (E1B-18K) proteins, as well as the E1B-16K protein, were precipitated from cell-free translations and from extracts of infected cells by antiserum against an amino terminal nonapeptide common to these proteins.
mesh_terms: D017456:Adenovirus Early Proteins; D000260:Adenoviruses, Human / Q000235:genetics*; D000595:Amino Acid Sequence; D000596:Amino Acids / Q000032:analysis; D000957:Antigens, Viral, Tumor / Q000235:genetics*; D002851:Chromatography, High Pressure Liquid; D004262:DNA Restriction Enzymes; D006367:HeLa Cells; D006801:Humans; D010446:Peptide Fragments / Q000032:analysis; D014176:Protein Biosynthesis; D012333:RNA, Messenger / Q000235:genetics; D014357:Trypsin; D014764:Viral Proteins / Q000235:genetics*
chemical_list: D017456:Adenovirus Early Proteins; D000596:Amino Acids; D000957:Antigens, Viral, Tumor; D010446:Peptide Fragments; D012333:RNA, Messenger; D014764:Viral Proteins; D004262:DNA Restriction Enzymes; D014357:Trypsin