alexa The carboxy-terminal domain of the LexA repressor oligomerises essentially as the entire protein.
Genetics & Molecular Biology

Genetics & Molecular Biology

Gene Technology

Author(s): Schnarr M, GrangerSchnarr M, Hurstel S, Pouyet J

Abstract Share this page

Abstract The ability of the isolated carboxy-terminal domain of the LexA repressor of Escherichia coli to form dimers and tetramers has been investigated by equilibrium ultracentrifugation. This domain, that comprises the amino acids 85-202, is readily purified after self-cleavage of the LexA repressor at alkaline pH. It turns out that the carboxy-terminal domain forms dimers and tetramers essentially as the entire LexA repressor. The corresponding association constants were determined after non-linear least squares fitting of the experimental concentration distribution. A dimer association constant of K2 = 3 X 10(4) M-1 and a tetramer association constant of K4 = 2 X 10(4) M-1 have been determined. Similar measurements on the entire LexA repressor [(1985) Biochemistry 24, 2812-2818] gave values of K2 = 2.1 X 10(4) M-1 and K4 = 7.7 X 10(4) M-1. Within experimental error the dimer formation constant of the carboxy-terminal domain may be considered to be the same as that of the entire repressor whereas the isolated domain forms tetramers slightly less efficiently. It should be stressed that the potential error in K4 is higher than that in K2. The overall conclusion is that the two structural domains of LexA have also well-defined functional roles: the amino-terminal domain interacts with DNA and the carboxy-terminal domain is involved in dimerisation reinforcing in this way the binding of the LexA repressor to operator DNA.
This article was published in FEBS Lett and referenced in Gene Technology

Relevant Expert PPTs

Relevant Speaker PPTs

Recommended Conferences

  • 2nd International Conference and Expo on Generic Drug Market and Contract Manufacturing
    September 25-26, 2017 Frankfurt, Germany
  • 6th International Conference and Exhibition on Cell and Gene Therapy
    Mar 27-28, 2017 Madrid, Spain
  • 2nd World Congress on Human Genetics & Genetic Disorders
    November 02-03, 2017 Toronto, Canada

Relevant Topics

Peer Reviewed Journals
Make the best use of Scientific Research and information from our 700 + peer reviewed, Open Access Journals
International Conferences 2017-18
Meet Inspiring Speakers and Experts at our 3000+ Global Annual Meetings

Contact Us

© 2008-2017 OMICS International - Open Access Publisher. Best viewed in Mozilla Firefox | Google Chrome | Above IE 7.0 version