Circular permutation analysis of phage T4 DNA by electron microscopy.
نویسندگان
چکیده
Phage T4 is known to have a linear duplex chromosome that is circularly permuted and terminally repeated. We found, by denaturation and self-reannealing experiments, that circular permutation in T4 native DNA is not random. Their multimodal distribution of permutation is compatible with the "headful packaging" model with the additional specifications that the encapsulation of DNA starts at several sites and these are not random distributed.
منابع مشابه
Non-random circular permutation of phage P22 DNA.
Phage P22 is known to have a linear duplex chromosome that is circularly permuted and terminally repeated. We have found, by constructing a partial denaturation map of mature P22 DNA, that circular permutation in P22 DNA is restricted: all of the ends of the mature DNA fall within 20% of each other on the physical map. The limited distribution of ends can be explained by the “headful” packaging...
متن کاملPartial denaturation mapping of phage T4 DNA at low temperature.
The partial-denaturation map of T4 DNA is obtained by using benzyldodecyldimethyl ammonium chloride in the presence of a high concentration of formamide. In this way suitable conditions for preparation of electron microscope specimens and partial denaturation within a temperature range low enough to minimize the endonucleolytic cleavage, are realized. It is found that, under our experimental co...
متن کاملStructure-function analysis of the DNA translocating portal of the bacteriophage T4 packaging machine.
Tailed bacteriophages and herpesviruses consist of a structurally well conserved dodecameric portal at a special 5-fold vertex of the capsid. The portal plays critical roles in head assembly, genome packaging, neck/tail attachment, and genome ejection. Although the structures of portals from phages φ29, SPP1, and P22 have been determined, their mechanistic roles have not been well understood. S...
متن کاملMolecular size and conformation of chloroplast deoxyribonucleic acid from pea leaves.
The molecular size and conformation of chloroplast (ct-) DNA has been studied by renaturation kinetics and electron microscopy. Ct-DNA of buoyant density 1.698 f 0.001 g per cm3 showed a T,, of 84” and a homogeneous melting pattern. Denatured and sheared c&DNA renatured as a single kinetic class with no suggestion of repeating sequences. Ct-DNA is found to have a molecular weight of 95 x lo6 by...
متن کاملDouble-length, circular, single-stranded DNA from filamentous phage.
Wild-type and gene 3 mutant filamentous phage stocks, containing different relative amounts of multiple-length particles, were treated exhaustively with DNase and then were highly purified. The phage DNA was extracted and examined by electron microscopy. In all cases, about 0.03% of the molecules were circular dimers. (3)H-labeled phage DNA was separated as to size by sedimentation in a preform...
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:
- Zeitschrift fur Naturforschung. Section C, Biosciences
دوره 38 3-4 شماره
صفحات -
تاریخ انتشار 1983