Complexed crystal structure of SSB reveals a novel single-stranded DNA binding mode (SSB)3:1: Phe60 is not crucial for defining binding paths

doi:10.1016/j.bbrc.2019.10.036

中山醫學大學機構典藏 CSMUIR > 醫學科技學院 > 生物醫學科學學系暨碩士班 > 期刊論文 > Item 310902500/20464

Please use this identifier to cite or link to this item: https://ir.csmu.edu.tw:8080/ir/handle/310902500/20464

Title:	Complexed crystal structure of SSB reveals a novel single-stranded DNA binding mode (SSB)3:1: Phe60 is not crucial for defining binding paths
Authors:	Huang, Y.-H. Lin, E.-S. Huang, C.-Y.
Contributors:	中山醫學大學生物醫學科學學系（所）
Keywords:	DNA-Binding Proteins;DNA, Single-Stranded;Proteins SSBs
Date:	2019-12
Issue Date:	2019-11-21T03:17:21Z (UTC)
Publisher:	Biochemical and Biophysical Research Communications
ISSN:	0006-291X
Abstract:	Single-stranded DNA-binding protein (SSB) is essential to cells as it participates in DNA metabolic processes, such as DNA replication, repair, and recombination. Escherichia coli SSB (EcSSB) tetramer cooperatively binds and wraps ssDNA in two major binding modes. In this study, we report the complex crystal structure of Pseudomonas aeruginosa SSB (PaSSB) with ssDNA dT20 at 2.39 Å resolution (PDB entry 6JDG) that revealed a new binding mode, namely, (SSB)3:1. In the (SSB)65 mode revealed by the EcSSB–dC35 complex structure, all four subunits fully participate in the binding to ssDNA. However, only three subunits in the PaSSB tetramer can participate in wrapping ssDNA in the (SSB)3:1 mode. The bound ssDNA in the PaSSB–ssDNA complex adopts an Ω-shaped conformation rather than a χ-shaped conformation in the (SSB)65 mode possibly due to the disability of Phe60. Phe60 is known to play a critical role in defining DNA-binding paths and promoting the wrapping of ssDNA around SSB tetramers. However, it is not important in the (SSB)3:1 mode. The ssDNA binding path revealed by our structural evidence suggests that ssDNA occupies half of the binding sites of the two subunits and slightly comes into contact with the ssDNA binding sites of the third subunit. Accordingly, we propose and sketch a possible wrapping mechanism of SSB via this novel ssDNA-binding mode, (SSB)3:1. © 2019 Elsevier Inc.
URI:	https://ir.csmu.edu.tw:8080/ir/handle/310902500/20464
Relation:	Biochemical and Biophysical Research Communications, Volume 520, Issue 2, Pages 353-358
Appears in Collections:	[生物醫學科學學系暨碩士班] 期刊論文

Files in This Item:

File	Description	Size	Format
Complexed-crystal-structure-of-SSB-reveals-a-novel-singlestranded-DNA-binding-mode-SSB-Phe60-is-not-crucial-for-defining-binding-paths2019Biochemical-and-Biophysical-Research-Communications.pdf		2628Kb	Adobe PDF	132	View/Open

View Licence

Loading...