5FHG

Structure of unliganded Pif1 from Bacteroides sp

Summary for 5FHG

• Entry DOI: 10.2210/pdb5fhg/pdb
• Related: 5FHD 5FHE 5FHF 5FHH
• Descriptor: Uncharacterized protein (2 entities in total)
• Functional Keywords: pif1 helicase, dna helicase, hydrolase
• Biological source: Bacteroides sp. 2_1_16
• Total number of polymer chains: 2
• Total formula weight: 99433.88

Authors

Zhou, X.,Ren, W.,Bharath, S.R.,Song, H. (deposition date: 2015-12-22, release date: 2016-03-30, Last modification date: 2024-03-20)

Primary citation

Zhou, X.,Ren, W.,Bharath, S.R.,Tang, X.,He, Y.,Chen, C.,Liu, Z.,Li, D.,Song, H.
Structural and Functional Insights into the Unwinding Mechanism of Bacteroides sp Pif1
Cell Rep, 14:2030-2039, 2016

PubMed Abstract: Pif1 is a conserved SF1B DNA helicase involved in maintaining genome stability through unwinding double-stranded DNAs (dsDNAs), DNA/RNA hybrids, and G quadruplex (G4) structures. Here, we report the structures of the helicase domain of human Pif1 and Bacteroides sp Pif1 (BaPif1) in complex with ADP-AlF4(-) and two different single-stranded DNAs (ssDNAs). The wedge region equivalent to the β hairpin in other SF1B DNA helicases folds into an extended loop followed by an α helix. The Pif1 signature motif of BaPif1 interacts with the wedge region and a short helix in order to stabilize these ssDNA binding elements, therefore indirectly exerting its functional role. Domain 2B of BaPif1 undergoes a large conformational change upon concomitant binding of ATP and ssDNA, which is critical for Pif1's activities. BaPif1 cocrystallized with a tailed dsDNA and ADP-AlF4(-), resulting in a bound ssDNA bent nearly 90° at the ssDNA/dsDNA junction. The conformational snapshots of BaPif1 provide insights into the mechanism governing the helicase activity of Pif1.

PubMed: 26904952
DOI: 10.1016/j.celrep.2016.02.008

Experimental method

X-RAY DIFFRACTION (2 Å)