Role of gpFI Protein in DNA Packaging by Bacteriophage .lambda.

Biochemistry ◽  
1995 ◽  
Vol 34 (31) ◽  
pp. 10036-10042 ◽  
Author(s):  
Carlo Enrique Catalano ◽  
Mary Ann Tomka

Genetics ◽  
1983 ◽  
Vol 104 (4) ◽  
pp. 549-570
Author(s):  
Ichizo Kobayashi ◽  
Mary M Stahl ◽  
David Leach ◽  
Franklin W Stahl

ABSTRACT Chi (5′-GCTGGTGG) is a recombinator in RecA- RecBC-mediated recombination in Escherichia coli. In bacteriophage λ vegetative recombination, Chi is fully active only when it is correctly oriented with respect to cos, the site that defines the ends of the packaged chromosome. Here we demonstrate that packaging from cos is not necessary for this cos-Chi interaction. Our evidence suggests that correctly oriented cos is an activator of Chi. cos, as an activator, is (1) dominant over cos  -, (2) active opposite an extensive heterology, (3) able to interact with Chi only when on the same (cis) chromosome, and (4) able to interact with Chi at distances as far as ≥ 20 kb. Thus, cos and Chi form a two-component recombinator system for general recombination. cos may serve as an asymmetric entry site for a recombination enzyme that recognizes Chi in an asymmetric way.



1978 ◽  
Vol 126 (3) ◽  
pp. 333-346 ◽  
Author(s):  
Michael Syvanen ◽  
Jerry Yin


Virology ◽  
1975 ◽  
Vol 64 (1) ◽  
pp. 247-263 ◽  
Author(s):  
Peter Ray ◽  
Helios Murialdo
Keyword(s):  


1976 ◽  
Vol 70 (1) ◽  
pp. 302-309 ◽  
Author(s):  
P.K. Mukherjee ◽  
R.K. Mandal




Genetics ◽  
1984 ◽  
Vol 108 (4) ◽  
pp. 773-794
Author(s):  
Ichizo Kobayashi ◽  
Mary M Stahl ◽  
Frederic R Fairfield ◽  
Franklin W Stahl

ABSTRACT Chi (Χ, 5'-GCTGGTGG) is a recombinator in RecA- and RecBC-mediated recombination in Escherichia coli. In vegetative recombination between two bacteriophage lambda strains, one with and the other without Chi (a  +Χ+  b  - × a-Χob+), the Χ-containing recombinant (a  -Χ+  b  -) is less abundant than the non-Χ-containing recombinant (a+Χob+). Previously this was taken was evidence for nonreciprocality of Χ-stimulated exchange. This inequality, however, is now seen to result from an event at cos (λ's packaging origin) that both activates Chi and initiates DNA packaging. An event at rightward cos leads to activation of leftward Χ on the same chromosome for an exchange to its left. From the resulting circulating dimer (-cos-a+-Χo-b+-cos-a--Χ+-b—), the cos that activated Χ is more likely to be used for rightward packaging initiation than is the cos from the other parent. Consistent with this coupling model is "biased packaging" in λ carrying two cos sites per monomer genome. When their maturation is dependent on dimerization by Χ-stimulated exchange, the phage particles result more often from packaging from the cos that activates Χ than from packaging from the other cos. Since Chi activation and packaging can be uncoupled, we infer that some early and reversible step in packaging activates Χ. A strong candidate for this step is a double-strand break at cos that provides an oriented entry site for a recombinase.



Sign in / Sign up

Export Citation Format

Share Document