TY - JOUR
T1 - lac repressor forms loops with linear DNA carrying two suitably spaced lac operators.
AU - Krämer, H.
AU - Niemöller, M.
AU - Amouyal, M.
AU - Revet, B.
AU - von Wilcken-Bergmann, B.
AU - Müller-Hill, B.
N1 - Copyright:
This record is sourced from MEDLINE/PubMed, a database of the U.S. National Library of Medicine
PY - 1987/5
Y1 - 1987/5
N2 - Tetrameric lac repressor may bind to two lac operators on one DNA fragment and induce the intervening DNA to form a loop. Electron microscopy, non-denaturing polyacrylamide gel electrophoresis, and DNase I protection experiments were used to demonstrate such DNA loops, where the distance between the centres of symmetry of the two lac operators varies between 63 and 535 bp. Formation of a DNA loop is favoured by correct phasing of the two lac operators and a low concentration of both components of the reaction. When a large excess of lac repressor over DNA is used, a 'tandem' structure is observed, in which both lac operators are occupied independently by two repressor tetramers. When the concentrations of both lac repressor and lac operator are high, a 'sandwich' structure is observed, in which two DNA molecules are connected by two lac repressor tetramers in trans.
AB - Tetrameric lac repressor may bind to two lac operators on one DNA fragment and induce the intervening DNA to form a loop. Electron microscopy, non-denaturing polyacrylamide gel electrophoresis, and DNase I protection experiments were used to demonstrate such DNA loops, where the distance between the centres of symmetry of the two lac operators varies between 63 and 535 bp. Formation of a DNA loop is favoured by correct phasing of the two lac operators and a low concentration of both components of the reaction. When a large excess of lac repressor over DNA is used, a 'tandem' structure is observed, in which both lac operators are occupied independently by two repressor tetramers. When the concentrations of both lac repressor and lac operator are high, a 'sandwich' structure is observed, in which two DNA molecules are connected by two lac repressor tetramers in trans.
UR - http://www.scopus.com/inward/record.url?scp=0023333893&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0023333893&partnerID=8YFLogxK
U2 - 10.1002/j.1460-2075.1987.tb02390.x
DO - 10.1002/j.1460-2075.1987.tb02390.x
M3 - Article
C2 - 3301328
AN - SCOPUS:0023333893
SN - 0261-4189
VL - 6
SP - 1481
EP - 1491
JO - The EMBO journal
JF - The EMBO journal
IS - 5
ER -