Product Details
| MW: | ~18kDa |
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| Source: | Produced in E. coli. |
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| UniProt ID: | P62837 |
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| Formulation: | Liquid. In 20mM TRIS-HCl, pH7.5, containing 0.5mM DTT. |
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| Biological Activity: | The His6-tagged fusion proteins of UbcH5a, UbcH5b and UbcH5c all charge and support ubiquitinylation in vitro. Unlike their GST-tagged counterparts, the His6-tagged UbcH5 family members all appear to form thiol ester conjugates with ubiquitin at a similar rate under similar conditions. The [C85A] mutation completely abolishes the ability of the enzyme to form a thiol ester and thereby acts as an excellent negative control. |
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| Application Notes: | Negative control for ubiquitin conjugating enzyme UbcH5b (Prod. No. BML-UW9060). The [C85A] mutation completely abolishes the ability of the enzyme to form a thiol ester. |
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| Shipping: | Shipped on Dry Ice |
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| Long Term Storage: | -80°C |
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| Use/Stability: | Enzyme is stable to multiple freeze/thaw cycles. |
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| Scientific Background: | A number of E2s in Saccharomyces cerevisiaem and their homologues have been identified. One such family of E2s is the UBC4/5, characterised as essential for the degradation of short-lived, regulatory and abnormal proteins. Protein levels of S. cerevisiae UbC4/5 are up-regulated in response to stress, and their loss results in severe effects on cellular functions.
A human gene product that is 79% identical to S. cerevisiae UBC4/5 in amino-acid sequence was identified as UbcH5a. In addition, two other human members of this highly conserved E2 class were also cloned and designated as UbcH5b and UbcH5c, having 88% and 89% identity to UbcH5a, respectively. Members of the UbcH5a/b/c are the most active class of E2s in cell extracts. The importance of this enzyme class is underscored by the critical role of UBC4/5 in S. cerevisiae. UbcH5a stimulates the conjugation of ubiquitin to the tumour-repressor p53 in the presence of E6-AP and E6. Moreover, UbcH5 family is implicated in c-fos recognition, the modulation of which is controlled by the ubiquitin-proteasome pathway. UbcH5b and UbcH5c are associated with the signal-induced conjugation and subsequent degradation of IkBα in the presence of the SCF complexes. UbcH5c also catalyses the ubiquitination leading to the processing of p105 precursor to form p50, a subunit of the heterodimeric transcription factor NF-kB. The range and diversity of substrates and E3s with which this class of E2 enzymes interact, suggest their complex roles in cellular functions require to be studied further. |
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| Regulatory Status: | RUO - Research Use Only |
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General Literature References
Identification of the ubiquitin carrier proteins, E2s, involved in signal-induced conjugation and subsequent degradation of IkappaBalpha: H. Gonen et al.; J. Biol. Chem. 274, 14823 (1999),
Enzymes catalyzing ubiquitination and proteolytic processing of the p105 precursor of nuclear factor kappaB1. : Coux, O. and Goldberg, A.L.; J. Biol. Chem. 273, 8820-8 (1998),
Degradation of the proto-oncogene c-Fos by the ubiquitin proteolytic system in vivo and in vitro: identification and characterisation of the conjugating enzymes: I. Stancovski et al.; Mol. Cel. Biol. 15, 7106 (1995),
Identification of a family of closely related human ubiquitin conjugating enzymes: J.P. Jensen et al.; J. Biol. Chem. 270, 30408 (1995),
Identification of a human ubiquitin-conjugating enzyme that mediates the E6-AP-dependent ubiquitination of p53. : Scheffner, M.; Proc. Natl. Acad. Sci. USA 91, 8797-8801 (1994),
The ubiquitin-conjugation system. : Jentsch, S. ; Annu. Rev. Genet. 22, 179-207 (1992),
Ubiquitin-conjugating enzymes UBC4 and UBC5 mediate selective degradation of short-lived and abnormal proteins. : Seufert, W. and Jentsch, S.; EMBO J. 9, 543-50 (1990),
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