2iy0: Difference between revisions

[[Image:2iy0.gif|left|200px]]<br /><applet load="2iy0" size="350" color="white" frame="true" align="right" spinBox="true"  

Small ubiquitin-like modifier (SUMO)-specific protease SENP1 processes SUMO-1, SUMO-2 and SUMO-3 to mature forms and deconjugates them from modified proteins. To establish the proteolytic mechanism, we determined structures of catalytically inactive SENP1 bound to SUMO-1-modified RanGAP1 and to unprocessed SUMO-1. In each case, the scissile peptide bond is kinked at a right angle to the C-terminal tail of SUMO-1 and has the cis configuration of the amide nitrogens. SENP1 preferentially processes SUMO-1 over SUMO-2, but binding thermodynamics of full-length SUMO-1 and SUMO-2 to SENP1 and K(m) values for processing are very similar. However, k(cat) values differ by 50-fold. Thus, discrimination between unprocessed SUMO-1 and SUMO-2 by SENP1 is based on a catalytic step rather than substrate binding and is likely to reflect differences in the ability of SENP1 to correctly orientate the scissile bonds in SUMO-1 and SUMO-2.

2IY0 is a [http://en.wikipedia.org/wiki/Protein_complex Protein complex] structure of sequences from [http://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2IY0 OCA].  

[[Category: Naismith, J H.]]

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