1vyx: Difference between revisions

[[Image:1vyx.gif|left|200px]]<br /><applet load="1vyx" size="350" color="white" frame="true" align="right" spinBox="true"  

RING domains are found in a large number of eukaryotic proteins. Most function as E3 ubiquitin-protein ligases, catalyzing the terminal step in the ubiquitination process. Structurally, these domains have been characterized as binding two zinc ions in a stable cross-brace motif. The tumorigenic human gamma-herpesvirus Kaposi's sarcoma-associated herpesvirus encodes a ubiquitin-protein ligase termed K3, which functions as an immune evasion molecule by ubiquitinating major histocompatibility complex class I. K3 possesses at its N terminus a domain related to cellular RING domains but with an altered zinc ligand arrangement. This domain was initially characterized as a plant homeodomain, a structure not previously known to function as an E3. Here, it is conclusively demonstrated that the K3 N-terminal domain is a variant member of the RING domain family and not a plant homeodomain. The domain is found to interact with the cellular ubiquitin-conjugating enzymes UbcH5A to -C and UbcH13, which dock to the equivalent surface as on classical cellular RING domains. Interaction with UbcH13 suggests a possible role for K3 in catalyzing Lys(63)-linked ubiquitination.

1VYX is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Human_herpesvirus_4 Human herpesvirus 4] with <scene name='pdbligand=ZN:'>ZN</scene> as [http://en.wikipedia.org/wiki/ligand ligand]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1VYX OCA].  

[[Category: Allen, M D.]]

[[Category: Brown, S E.]]

[[Category: Dodd, R B.]]

[[Category: Duncan, L M.]]

[[Category: Lehner, P J.]]

[[Category: Read, R J.]]

[[Category: Sanderson, C M.]]

''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 15:38:45 2008''