2gaf: Difference between revisions

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

Polyadenylation of mRNAs in poxviruses, crucial for virion maturation, is carried out by a poly(A) polymerase heterodimer composed of a catalytic component, VP55, and a processivity factor, VP39. The ATP-gamma-S bound and unbound crystal structures of the vaccinia polymerase reveal an unusual architecture for VP55 that comprises of N-terminal, central or catalytic, and C-terminal domains with different topologies and that differs from many polymerases, including the eukaryotic poly(A) polymerases. Residues in the active site of VP55, located between the catalytic and C-terminal domains, make specific interactions with the adenine of the ATP analog, establishing the molecular basis of ATP recognition. VP55's concave surface docks the globular VP39. A model for RNA primer binding that involves all three VP55 domains and VP39 is proposed. The model supports biochemical evidence that VP39 functions as a processivity factor by partially enclosing the RNA primer at the heterodimer interface.

2GAF is a [http://en.wikipedia.org/wiki/Protein_complex Protein complex] structure of sequences from [http://en.wikipedia.org/wiki/Vaccinia_virus Vaccinia virus]. Active as [http://en.wikipedia.org/wiki/mRNA_(nucleoside-2'-O-)-methyltransferase mRNA (nucleoside-2'-O-)-methyltransferase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=2.1.1.57 2.1.1.57] Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2GAF OCA].  

[[Category: Bowman, B R.]]

[[Category: Gershon, P D.]]

[[Category: Moure, C M.]]

[[Category: Quiocho, F A.]]

''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 17:29:45 2008''