PDBsum entry 5lb5

Hydrolase

PDB id: 5lb5

Contents

Protein chains

430 a.a.

Ligands

DMS ×3

ADP ×4

Metals

_ZN ×4

_MG ×4

Waters ×399

PDB id:

5lb5

Name:

Hydrolase

Title:

Crystal structure of human recql5 helicase in complex with adp/mg (tricilinc form).

Structure:

Atp-dependent DNA helicase q5. Chain: a, b, c, d. Synonym: DNA helicase,recq-like type 5,recq5,recq protein-like 5. Engineered: yes

Source:

Homo sapiens. Human. Organism_taxid: 9606. Gene: recql5, recq5. Expressed in: escherichia coli bl21(de3). Expression_system_taxid: 469008

Resolution:

2.00Å R-factor: 0.246 R-free: 0.282

Authors:

J.A.Newman,H.Aitkenhead,P.Savitsky,T.Krojer,F.Von Delft, C.H.Arrowsmith,A.M.Edwards,C.Bountra,O.Gileadi,Structural Genomics Consortium (Sgc)

Key ref:

J.A.Newman et al. (2017). Insights into the RecQ helicase mechanism revealed by the structure of the helicase domain of human RECQL5. Nucleic Acids Res, 45, 4231-4243. PubMed id: 28100692

Date:

15-Jun-16 Release date: 06-Jul-16

Protein chains

O94762  (RECQ5_HUMAN) -  ATP-dependent DNA helicase Q5 from Homo sapiens

Seq: 991 a.a.

Struc: 430 a.a.

Enzyme reactions

• Enzyme class: E.C.5.6.2.4 - Dna 3'-5' helicase.

Nucleic Acids Res 45:4231-4243 (2017)

PubMed id: 28100692

Insights into the RecQ helicase mechanism revealed by the structure of the helicase domain of human RECQL5.

J.A.Newman, H.Aitkenhead, P.Savitsky, O.Gileadi.

ABSTRACT

RecQ helicases are important maintainers of genome integrity with distinct roles in almost every cellular process requiring access to DNA. RECQL5 is one of five human RecQ proteins and is particularly versatile in this regard, forming protein complexes with a diverse set of cellular partners in order to coordinate its helicase activity to various processes including replication, recombination and DNA repair. In this study, we have determined crystal structures of the core helicase domain of RECQL5 both with and without the nucleotide ADP in two distinctly different ('Open' and 'Closed') conformations. Small angle X-ray scattering studies show that the 'Open' form of the protein predominates in solution and we discuss implications of this with regards to the RECQL5 mechanism and conformational changes. We have measured the ATPase, helicase and DNA binding properties of various RECQL5 constructs and variants and discuss the role of these regions and residues in the various RECQL5 activities. Finally, we have performed a systematic comparison of the RECQL5 structures with other RecQ family structures and based on these comparisons we have constructed a model for the mechano-chemical cycle of the common catalytic core of these helicases.