ジャーナル: Nucleic Acids Res / 年: 2013 タイトル: Tracking in atomic detail the functional specializations in viral RecA helicases that occur during evolution. 著者: Kamel El Omari / Christoph Meier / Denis Kainov / Geoff Sutton / Jonathan M Grimes / Minna M Poranen / Dennis H Bamford / Roman Tuma / David I Stuart / Erika J Mancini / 要旨: Many complex viruses package their genomes into empty protein shells and bacteriophages of the Cystoviridae family provide some of the simplest models for this. The cystoviral hexameric NTPase, P4, ...Many complex viruses package their genomes into empty protein shells and bacteriophages of the Cystoviridae family provide some of the simplest models for this. The cystoviral hexameric NTPase, P4, uses chemical energy to translocate single-stranded RNA genomic precursors into the procapsid. We previously dissected the mechanism of RNA translocation for one such phage, 12, and have now investigated three further highly divergent, cystoviral P4 NTPases (from 6, 8 and 13). High-resolution crystal structures of the set of P4s allow a structure-based phylogenetic analysis, which reveals that these proteins form a distinct subfamily of the RecA-type ATPases. Although the proteins share a common catalytic core, they have different specificities and control mechanisms, which we map onto divergent N- and C-terminal domains. Thus, the RNA loading and tight coupling of NTPase activity with RNA translocation in 8 P4 is due to a remarkable C-terminal structure, which wraps right around the outside of the molecule to insert into the central hole where RNA binds to coupled L1 and L2 loops, whereas in 12 P4, a C-terminal residue, serine 282, forms a specific hydrogen bond to the N7 of purines ring to confer purine specificity for the 12 enzyme.
Component-ID: _ / Beg auth comp-ID: MET / Beg label comp-ID: MET / End auth comp-ID: LEU / End label comp-ID: LEU / Refine code: _ / Auth seq-ID: 1 - 328 / Label seq-ID: 1 - 328
解像度: 2.4→38.46 Å / Cor.coef. Fo:Fc: 0.84 / Cor.coef. Fo:Fc free: 0.836 / SU B: 19.425 / SU ML: 0.213 / 交差検証法: THROUGHOUT / ESU R: 0.725 / ESU R Free: 0.34 / 立体化学のターゲット値: MAXIMUM LIKELIHOOD / 詳細: HYDROGENS HAVE BEEN ADDED IN THE RIDING POSITIONS.
Rfactor
反射数
%反射
Selection details
Rfree
0.28977
1844
5.1 %
RANDOM
Rwork
0.26269
-
-
-
obs
0.26402
34261
83.42 %
-
溶媒の処理
イオンプローブ半径: 0.8 Å / 減衰半径: 0.8 Å / VDWプローブ半径: 1.2 Å / 溶媒モデル: MASK