The primary structures of four subunits of the human, high-molecular-weight proteinase, macropain (proteasome), are distinct but homologous

George N. DeMartino, Kim Orth, Marci L. McCullough, Lawrence W. Lee, Terry Z. Munn, Carolyn R. Moomaw, Paul A. Dawson, Clive A. Slaughter

Research output: Contribution to journalArticlepeer-review

52 Scopus citations

Abstract

Macropain (proteasome) is a high-molecular-weight proteinase complex composed of at least 13 electrophoretically distinct subunits. Previous work, including peptide mapping and limited amino acid sequencing, suggested that most of the subunits belong to an evolutionarily related group of different gene products (Lee et al. (1990) Biochim. Biophys. Acta. 1037, 178-185). In order to define the extent and pattern of subunit relatedness, and to determine the structural basis for possible similarities and differences in subunit functions, we are deducing the primary structures of macropain subunits by cDNA cloning and DNA sequence analysis. We report here the primary structures of four subunits. The data clearly demonstrate that the proteins represent different, but homologous gene products. Surprisingly, no evidence for homology with any other protein, including proteinases, was obtained. These results suggest that macropain is comprised of a previously unidentified family of evolutionarily related polypeptides. Because biochemical data indicate that macropain contains several different proteinase activities, the current results raise the possibility that the macropain complex is composed of a group of novel proteinases, distinct from those of other structurally identifiable proteinase families.

Original languageEnglish (US)
Pages (from-to)29-38
Number of pages10
JournalBiochimica et Biophysica Acta (BBA)/Protein Structure and Molecular
Volume1079
Issue number1
DOIs
StatePublished - Aug 9 1991
Externally publishedYes

Keywords

  • Macropain
  • Multicatalytic proteinase
  • Proteasome
  • Ubiquitin

ASJC Scopus subject areas

  • Molecular Biology
  • Structural Biology
  • Biophysics
  • Biochemistry

Fingerprint

Dive into the research topics of 'The primary structures of four subunits of the human, high-molecular-weight proteinase, macropain (proteasome), are distinct but homologous'. Together they form a unique fingerprint.

Cite this