PROTEIN-INDUCED BENDING AND DNA CYCLIZATION
PROTEIN-INDUCED BENDING AND DNA CYCLIZATION
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DOI:
10.1073/pnas.89.14.6343
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发表时间:
1992-07-15
影响因子:
11.1
通讯作者:
CROTHERS, DM
中科院分区:
文献类型:
--
作者:
KAHN, JD;CROTHERS, DM
We have applied T4 ligase-mediated DNA cyclization kinetics to protein-induced bending in DNA. The presence and direction of a static bend can be inferred from J factors for cyclization of 150- to 160-base-pair minicircles, which include a catabolite activator protein binding site phased against a sequence-directed bend. We demonstrate a quasi-thermodynamic linkage between cyclization and protein binding; we find that properly phased DNAs bind catabolite activator protein almost-equal-to 200-fold more tightly as circles than as linear molecules. The results unambiguously distinguish DNA bends from isotropically flexible sites and can explain cooperative binding by proteins that need not contact each other.