Putting Two Heads Together to Unwind DNA
نویسندگان
چکیده
The loading of replicative helicases onto DNA is tightly regulated in all organisms, yet the molecular mechanisms for this event remain poorly defined. Remus et al. (2009) provide important insights into helicase loading in eukaryotes, showing that the Mcm2-7 replicative helicase encircles double-stranded DNA as head-to-head double hexamers.
منابع مشابه
Functional and physical interaction between WRN helicase and human replication protein A.
The human premature aging disorder Werner syndrome (WS) is associated with a large number of symptoms displayed in normal aging. The WRN gene product, a DNA helicase, has been previously shown to unwind short DNA duplexes (</=53 base pairs) in a reaction stimulated by single-stranded DNA-binding proteins. We have studied the helicase activity of purified WRN protein on a variety of DNA duplex s...
متن کاملHuman HEL308 Localizes to Damaged Replication Forks and Unwinds Lagging Strand Structures*
HEL308 is a superfamily II DNA helicase, conserved from archaea through to humans. HEL308 family members were originally isolated by their similarity to the Drosophila melanogaster Mus308 protein, which contributes to the repair of replication-blocking lesions such as DNA interstrand cross-links. Biochemical studies have established that human HEL308 is an ATP-dependent enzyme that unwinds DNA ...
متن کاملA Sisyphean helicase
JCB • VOLUME 171 • NUMBER 4 • 2005 582 A Sisyphean helicase ome helicases continually bang their heads against the wall, if a new report from Sua Myong, Taekjip Ha (University of Illinois, UrbanaChampaign, IL), and colleagues is any indication. The Rep helicase, the group finds, repeatedly motors along a track of DNA, hits an obstacle, and returns to square one. Not all helicases can unwind DNA...
متن کاملSimian virus 40 large T antigen can specifically unwind the central palindrome at the origin of DNA replication.
The hydrophilic channels between helicase domains of simian virus 40 (SV40) large T antigen play a critical role in DNA replication. Previous mutagenesis of residues in the channels identified one class of mutants (class A: D429A, N449S, and N515S) with normal DNA binding and ATPase and helicase activities but with a severely reduced ability to unwind origin DNA and to support SV40 DNA replicat...
متن کاملBinding of meso-tetra (4-N-methylpyridyl) porphine to DNA.
The porphyrin photosensitizer, meso-Tetra (4-N-methyl-pyridyl) porphine tetraperchlorate is shown to unwind supercoiled ColEI DNA at a somewhat lower concentration than ethidium bromide. In contrast to this, the Fe(III) chelate of T4MPyP cannot unwind supercoiled DNA. It is concluded that these results corroborate our previous findings that, despite its large bulk, T4MPyP is fully capable of in...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید
ثبت ناماگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید
ورودعنوان ژورنال:
- Cell
دوره 139 شماره
صفحات -
تاریخ انتشار 2009