Control of bacterial DNA supercoiling
نویسندگان
چکیده
منابع مشابه
DNA supercoiling inhibits DNA knotting
Despite the fact that in living cells DNA molecules are long and highly crowded, they are rarely knotted. DNA knotting interferes with the normal functioning of the DNA and, therefore, molecular mechanisms evolved that maintain the knotting and catenation level below that which would be achieved if the DNA segments could pass randomly through each other. Biochemical experiments with torsionally...
متن کاملStructural insight into negative DNA supercoiling by DNA gyrase, a bacterial type 2A DNA topoisomerase
Type 2A DNA topoisomerases (Topo2A) remodel DNA topology during replication, transcription and chromosome segregation. These multisubunit enzymes catalyze the transport of a double-stranded DNA through a transient break formed in another duplex. The bacterial DNA gyrase, a target for broad-spectrum antibiotics, is the sole Topo2A enzyme able to introduce negative supercoils. We reveal here for ...
متن کاملDNA knots and DNA supercoiling.
Type II DNA topoisomerases permit passages of double stranded DNA segments through each other and this is achieved via a complex mechanism involving a transient cleavage of one duplex, a passage of the second duplex through the topoisomerase-spanned cleavage site and finally resealing of the cut duplex. Type II DNA topoisomerases facilitate many DNA transactions requiring manipulation of long D...
متن کاملSupercoiling DNA Locates Mismatches.
We present a method of detecting sequence defects by supercoiling DNA with magnetic tweezers. The method is sensitive to a single mismatched base pair in a DNA sequence of several thousand base pairs. We systematically compare DNA molecules with 0 to 16 adjacent mismatches at 1 M monovalent salt and 3.6 pN force and show that under these conditions, a single plectoneme forms and is stably pinne...
متن کاملFluctuations and supercoiling of DNA.
Frequently, DNA in vivo is organized into loops that are partially underwound and consequently form interwound helical supercoils. Methods from polymer statistical mechanics are used to show how the competition between entropy (thermal fluctuations) and elastic energy determines supercoil radius and pitch, in good agreement with recent experiments and simulations. Supercoil reorganization by me...
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ژورنال
عنوان ژورنال: Molecular Microbiology
سال: 1992
ISSN: 0950-382X,1365-2958
DOI: 10.1111/j.1365-2958.1992.tb01486.x