English   español  
Please use this identifier to cite or link to this item: http://hdl.handle.net/10261/3557
logo share SHARE logo core CORE   Add this article to your Mendeley library MendeleyBASE

Visualizar otros formatos: MARC | Dublin Core | RDF | ORE | MODS | METS | DIDL
Exportar a otros formatos:


A Bacterial TrwC Relaxase Domain Contains a Thermally Stable α-Helical Core

AuthorsArrondo, José Luis R.; Echabe, Izaskun; Iloro, Ibon; Hernando, Miguel Ángel ; Cruz, Fernando de la ; Goñi, Félix M.
Issue DateJul-2003
PublisherAmerican Society for Microbiology
CitationJournal of Bacteriology 185(14): 4226–4232 (2003)
AbstractThe TrwC protein is the relaxase-helicase responsible for the initiation and termination reactions of DNA processing during plasmid R388 conjugation. The TrwC-N275 fragment comprises the 275-amino-acid Nterminal domain of the protein that contains the DNA cleavage and strand transfer activities (the relaxase domain). It can be easily purified by keeping a cell lysate at 90°C for 10 min. Infrared spectroscopy shows that this domain has a predominantly / structure with some amount of unordered structure. Fast heating and cooling does not change the secondary structure, whereas slow heating produces two bands in the infrared spectrum characteristic of protein aggregation. The denaturation temperature is increased in the protein after the fast-heating thermal shock. Two-dimensional infrared correlation spectroscopy shows that thermal unfolding is a very cooperative two-state process without any appreciable steps prior to aggregation. After aggregation, the -helix percentage is not altered and -helix signal does not show in the correlation maps, meaning that the helices are not affected by heating. The results indicate that the domain has an -helix core resistant to temperature and responsible for folding after fast heating and an outer layer of -sheet and unordered structure that aggregates under slow heating. The combination of a compact core and a flexible outer layer could be related to the structural requirements of DNA-protein binding.
Publisher version (URL)http://dx.doi.org/10.1128/JB.185.14.4226–4232.2003
Appears in Collections:(UBF) Artículos
(CIB) Artículos
Files in This Item:
There are no files associated with this item.
Show full item record
Review this work

Related articles:

WARNING: Items in Digital.CSIC are protected by copyright, with all rights reserved, unless otherwise indicated.