RuvABC is a complex of three protein s that mediate branch migration and resolve the Holliday junction created during Homologous recombination In bacteria homologous recombination in bacteria. As such, RuvABC is critical to bacterial DNA repair . RuvA and RuvB bind to the four strand DNA structure formed in the Holliday junction intermediate, and migrate the strands through each other, using a putative spooling mechanism. The binding of the RuvC protein to the RuvAB complex is thought to cleave the DNA strands, thereby resolving the Holliday junction. The structure of the complex has been variously elucidated through X ray crystallography and EM data, and suggest that the complex consists of either one or two RuvA tetramers, with charge lined grooves through which the incoming DNA is channelled. The structure also showed the presence of so called acidic pins in the centre of the tetramer, which serve to separate the DNA duplexes. The RuvB proteins are thought to form hexameric rings on the exit points of the newly formed DNA duplexes, and it is proposed that they spool the emerging DNA through the RuvA tetramer. RuvC is the resolvase, which cleaves the Holliday junction. It is thought to bind either on the open, DNA exposed face of a single RuvA tetramer, or to replace one of the two tetramers. Binding is proposed to be mediated by an unstructured loop on RuvC, which becomes structured on binding RuvA. RuvC can be bound to the complex in either orientation, therefore resolving Holliday junctions in either a horizontal or vertical manner. Sources cite journal author West SC title Molecular views of recombination proteins and their control journal Nat. Rev. Mol. Cell Biol. volume 4 issue 6 pages 435 45 year 2003 pmid 12778123 doi 10.1038 nrm1127 cite journal author Kowalczykowski SC title Initiation of genetic recombination and recombination dependent replication journal Trends Biochem. Sci. volume 25 issue 4 pages 156 65 year 2000 pmid 10754547 doi 10.1016 S0968 0004 ... more details
Branch migration describes the ability of a DNA strand partially paired with its complement in a duplex to extend its pairing by displacing the resident strand with which it is homologous. This usually happens when two homologous double strands form a Holliday junction and the whole structure slides into one direction the branch migrates . This procedure can influence the amount of information that is transferred between two recombining partners. In E. Coli RuvA and RuvB of the RuvABC protein complex promote branch migration until RuvC binds and resolves the Holliday junction by cleaving. Another definition for branch migration is the extension of a D loop when a single stranded DNA strand invades a recipient duplex during recombination or repair. Category Cellular processes Category Molecular genetics genetics stub ... more details
Image Holliday Junction.svg thumb 200px right Holliday Junction Image Holliday junction coloured.png thumb 200px right Molecular structure of a Holliday junction. From PDB 3CRX . A Holliday junction is a mobile junction between four strands of DNA . The structure is named after Robin Holliday , who proposed it in 1964 ref name Stahl cite journal author Stahl FW title The Holliday junction on its thirtieth anniversary journal Genetics volume 138 issue 2 date 1 October 1994 pages 241 246 format PDF url http www.genetics.org cgi reprint 138 2 241 pmid 7828807 pmc 1206142 ref ref name Liu2004 cite journal author Liu Y, West S title Happy Hollidays 40th anniversary of the Holliday junction journal Nat Rev Mol Cell Biol volume 5 issue 11 pages 937 44 year 2004 pmid 15520813 doi 10.1038 nrm1502 ref ref name Hays2003 cite journal title Caution DNA Crossing Crystal Structures of Holliday Junctions author Hays FA, Watson J, Ho PS journal J Biol Chem volume 278 issue 50 pages 49663 49666 year 2003 doi 10.1074 jbc.R300033200 pmid 14563836 ref to account for a particular type of exchange of genetic information he observed in yeast known as homologous recombination . Holliday junctions are highly conserved sequence conserved structures, from prokaryote s to mammal s. ref cite journal author Constantinou A, Davies AA, West SC title Branch migration and Holliday junction resolution catalyzed by activities from mammalian cells journal CELL volume 104 issue 2 year 2001 pages 259 268 pmid 11207366 doi 10.1016 S0092 8674 01 00210 0 ref Because these junctions are between homologous sequences, they can slide up and down the DNA. In bacteria , this sliding or branch migration is facilitated by the RuvABC complex or RecG protein, molecular motors that use the energy of Adenosine triphosphate ATP hydrolysis to push the junction around. The junction must then be resolved, split up, to restore 2 linear duplexes. This can be done to either restore the parental configuration or to establish a ... more details
cutting, swapping of strands, and ligation at the open arrowheads by some combination of RuvABC ... Resolution of the Holliday junction by some combination of RuvABC or RecG can produce two recombinant .... To catalyze branch migration, the RuvABC RuvA protein first recognizes and binds to the Holliday junction and recruits the RuvABC RuvB protein to form the RuvAB complex. Two sets of the RuvB ..., which together form the RuvABC complex. RuvC is an endonuclease that cuts the Codon Degeneracy of the genetic ... more details
For a non technical introduction to the topic Introduction to genetics Other uses pp vandalism expiry June 2, 2012 small yes pp move indef File DNA Structure Key Labelled.pn NoBB.png thumb right 340px The structure of the DNA double helix . The atoms in the structure are colour coded by Chemical element element and the detailed structure of two base pairs is shown in the bottom right. File ADN animation.gif thumb The structure of part of a DNA double helix Deoxyribonucleic acid IPAc en audio en us Deoxyribonucleic acid.ogg d i k s i r a b . n ju k l e . k s d DNA is a nucleic acid containing the genetics genetic instructions used in the development and functioning of all known living organism s with the exception of RNA virus es . The DNA segments carrying this genetic information are called gene s. Likewise, other DNA sequences have structural purposes, or are involved in regulating the use of this genetic information. Along with RNA and proteins , DNA is one of the three major macromolecules that are essential for all known forms of life . DNA consists of two long polymers of simple units called nucleotide s, with backbone chain backbone s made of Monosaccharide sugar s and phosphate groups joined by ester bonds. These two strands run in opposite directions to each other and are therefore antiparallel biochemistry anti parallel . Attached to each sugar is one of four types of molecules called nucleobases informally, bases . It is the Nucleic acid sequence sequence of these four nucleobases along the backbone that encodes information. This information is read using the genetic code , which specifies the sequence of the amino acid s within proteins. The code is read by copying stretches of DNA into the related nucleic acid RNA in a process called transcription genetics transcription . Within cells DNA is organized into long structures called chromosome s. During cell division these chromosomes are duplicated in the process of DNA replication , p ... more details
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