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PROSITE documentation PDOC00163 [for PROSITE entry PS50127]

Ubiquitin-conjugating enzymes signature and profile


Ubiquitin-conjugating enzymes (EC (UBC or E2 enzymes) [1,2,3] catalyze the covalent attachment of ubiquitin to target proteins. An activated ubiquitin moiety is transferred from an ubiquitin-activating enzyme (E1) to E2 which later ligates ubiquitin directly to substrate proteins with or without the assistance of 'N-end' recognizing proteins (E3).

In most species there are many forms of UBC (at least 9 in yeast) which are implicated in diverse cellular functions.

A cysteine residue is required for ubiquitin-thiolester formation. There is a single conserved cysteine in UBC's and the region around that residue is conserved in the sequence of known UBC isozymes. We have used that region as a signature pattern. We also developed a profile that spans the complete catalytical domain.

Expert(s) to contact by email:

Jentsch S.

Last update:

April 2006 / Pattern revised.

Technical section

PROSITE methods (with tools and information) covered by this documentation:

UBIQUITIN_CONJUGAT_2, PS50127; Ubiquitin-conjugating enzymes family profile  (MATRIX)

UBIQUITIN_CONJUGAT_1, PS00183; Ubiquitin-conjugating enzymes active site  (PATTERN)


1AuthorsJentsch S., Seufert W., Sommer T., Reins H.-A.
TitleUbiquitin-conjugating enzymes: novel regulators of eukaryotic cells.
SourceTrends Biochem. Sci. 15:195-198(1990).
PubMed ID2193438

2AuthorsJentsch S., Seufert W., Hauser H.-P.
TitleGenetic analysis of the ubiquitin system.
SourceBiochim. Biophys. Acta 1089:127-139(1991).
PubMed ID1647207

3AuthorsHershko A.
TitleThe ubiquitin pathway for protein degradation.
SourceTrends Biochem. Sci. 16:265-268(1991).
PubMed ID1656558

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