Small-angle X-ray Scattering Study of a Rex Family Repressor: Conformational Response to NADH and NAD(+) Binding in Solution.
Wang, Ellen LU ; Ikonen, Teemu P ; Knaapila, Matti LU ; Svergun, Dmitri ; Logan, Derek LU
and von Wachenfeldt, Claes
LU
(2011)
In Journal of Molecular Biology
408.
p.670-683
- Abstract
- The transcriptional repressor Rex is a sensor of the intracellular NADH/NAD(+) redox state through direct binding of NADH or NAD(+). Homodimeric Rex protein from Thermus aquaticus (T-Rex) and Bacillus subtilis (B-Rex) exists in several different conformations. In both organisms, Rex in complex with NADH has the DNA binding domains packed together at the dimer interface, whereas in the apo form of B-Rex the linkers connecting these domains to the core are flexible. The crystal structures of the apo forms of B-Rex and a mutated variant of T-Rex are radically different. We describe the solution structures of B-Rex in complex with NAD(+) or NADH and in its apo form, on the basis of small-angle X-ray scattering (SAXS) measurements. This study... (More)
- The transcriptional repressor Rex is a sensor of the intracellular NADH/NAD(+) redox state through direct binding of NADH or NAD(+). Homodimeric Rex protein from Thermus aquaticus (T-Rex) and Bacillus subtilis (B-Rex) exists in several different conformations. In both organisms, Rex in complex with NADH has the DNA binding domains packed together at the dimer interface, whereas in the apo form of B-Rex the linkers connecting these domains to the core are flexible. The crystal structures of the apo forms of B-Rex and a mutated variant of T-Rex are radically different. We describe the solution structures of B-Rex in complex with NAD(+) or NADH and in its apo form, on the basis of small-angle X-ray scattering (SAXS) measurements. This study addresses to what extent the unusual orientation of the DNA recognition domains of the crystal structure of apo B-Rex is owing to stabilization by crystal packing. Low-resolution ab initio solution structures were obtained for apo B-Rex, B-Rex:NADH and B-Rex:NAD(+). Models giving a more detailed picture of these three solution structures were obtained also by rigid body fitting of the crystallographic domains. The SAXS data confirm the elongated and flexible nature of apo-B-Rex and the existence of two distinct and more rigid conformations for the complexes with NADH and NAD(+). The models emerging from this study indicate a reaction mechanism for B-Rex in which the recognition domains are rotated upon binding to NADH. (Less)
Please use this url to cite or link to this publication:
https://lup.lub.lu.se/record/1883972
- author
- Wang, Ellen
LU
; Ikonen, Teemu P
; Knaapila, Matti
LU
; Svergun, Dmitri
; Logan, Derek
LU
and von Wachenfeldt, Claes
LU
- organization
- publishing date
- 2011
- type
- Contribution to journal
- publication status
- published
- subject
- in
- Journal of Molecular Biology
- volume
- 408
- pages
- 670 - 683
- publisher
- Elsevier
- external identifiers
-
- wos:000290501200007
- scopus:79955031175
- pmid:21402078
- ISSN
- 1089-8638
- DOI
- 10.1016/j.jmb.2011.02.050
- language
- English
- LU publication?
- yes
- id
- 81ce36b0-1f90-4b97-8326-3dfcd64090b8 (old id 1883972)
- date added to LUP
- 2016-04-01 10:14:04
- date last changed
- 2025-04-04 14:27:45
@article{81ce36b0-1f90-4b97-8326-3dfcd64090b8,
abstract = {{The transcriptional repressor Rex is a sensor of the intracellular NADH/NAD(+) redox state through direct binding of NADH or NAD(+). Homodimeric Rex protein from Thermus aquaticus (T-Rex) and Bacillus subtilis (B-Rex) exists in several different conformations. In both organisms, Rex in complex with NADH has the DNA binding domains packed together at the dimer interface, whereas in the apo form of B-Rex the linkers connecting these domains to the core are flexible. The crystal structures of the apo forms of B-Rex and a mutated variant of T-Rex are radically different. We describe the solution structures of B-Rex in complex with NAD(+) or NADH and in its apo form, on the basis of small-angle X-ray scattering (SAXS) measurements. This study addresses to what extent the unusual orientation of the DNA recognition domains of the crystal structure of apo B-Rex is owing to stabilization by crystal packing. Low-resolution ab initio solution structures were obtained for apo B-Rex, B-Rex:NADH and B-Rex:NAD(+). Models giving a more detailed picture of these three solution structures were obtained also by rigid body fitting of the crystallographic domains. The SAXS data confirm the elongated and flexible nature of apo-B-Rex and the existence of two distinct and more rigid conformations for the complexes with NADH and NAD(+). The models emerging from this study indicate a reaction mechanism for B-Rex in which the recognition domains are rotated upon binding to NADH.}},
author = {{Wang, Ellen and Ikonen, Teemu P and Knaapila, Matti and Svergun, Dmitri and Logan, Derek and von Wachenfeldt, Claes}},
issn = {{1089-8638}},
language = {{eng}},
pages = {{670--683}},
publisher = {{Elsevier}},
series = {{Journal of Molecular Biology}},
title = {{Small-angle X-ray Scattering Study of a Rex Family Repressor: Conformational Response to NADH and NAD(+) Binding in Solution.}},
url = {{http://dx.doi.org/10.1016/j.jmb.2011.02.050}},
doi = {{10.1016/j.jmb.2011.02.050}},
volume = {{408}},
year = {{2011}},
}