2lcj | pdb_00002lcj

Solution NMR structure of Pab PolII Intein

spinqualitylabelsall models 2lcj, 20 NMR models Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 2lcj is a 1 chain structure with sequence from Pyrab. Full experimental information is available from OCA. For a guided tour on the structure components use FirstGlance. Gene: polC, PYRAB01200, PAB2404 (PYRAB) Activity: DNA-directed DNA polymerase, with EC number 2.7.7.7 Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum Function [DP2L_PYRAB] Possesses two activities: a DNA synthesis (polymerase) and an exonucleolytic activity that degrades single-stranded DNA in the 3'- to 5'-direction. Has a template-primer preference which is characteristic of a replicative DNA polymerase (By similarity). Publication Abstract from PubMed Protein splicing is a precise self-catalyzed process in which an intein excises itself from a precursor with the concomitant ligation of the flanking polypeptides (exteins). Protein splicing proceeds through a four-step reaction but the catalytic mechanism is not fully understood at the atomic level. We report the solution NMR structures of the hyperthermophilic Pyrococcus abyssi PolII intein, which has a noncanonical C-terminal glutamine instead of an asparagine. The NMR structures were determined to a backbone root mean square deviation of 0.46 A and a heavy atom root mean square deviation of 0.93 A. The Pab PolII intein has a common HINT (hedgehog intein) fold but contains an extra beta-hairpin that is unique in the structures of thermophilic inteins. The NMR structures also show that the Pab PolII intein has a long and disordered loop in place of an endonuclease domain. The N-terminal Cys-1 amide is hydrogen bonded to the Thr-90 hydroxyl in the conserved block-B TXXH motif and the Cys-1 thiol forms a hydrogen bond with the block F Ser-166. Mutating Thr-90 to Ala dramatically slows N-terminal cleavage, supporting its pivotal role in promoting the N-S acyl shift. Mutagenesis also showed that Thr-90 and His-93 are synergistic in catalyzing the N-S acyl shift. The block F Ser-166 plays an important role in coordinating the steps of protein splicing. NMR spin relaxation indicates that the Pab PolII intein is significantly more rigid than mesophilic inteins, which may contribute to the higher optimal temperature for protein splicing. Structural and Mutational Studies of a Hyperthermophilic Intein from DNA Polymerase II of Pyrococcus abyssi.,Du Z, Liu J, Albracht CD, Hsu A, Chen W, Marieni MD, Colelli KM, Williams JE, Reitter JN, Mills KV, Wang C J Biol Chem. 2011 Nov 4;286(44):38638-48. Epub 2011 Sep 13. PMID:21914805 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

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