From owner-biophysics@net.bio.net Fri Feb 26 22:00:00 1999 Newsgroups: bionet.biophysics Path: biosci!agate!newsfeed.berkeley.edu!btnet-peer!btnet!nntp.news.xara.net!xara.net!server5.netnews.ja.net!leeds.ac.uk!news From: bmbjmm@bmb.leeds.ac.uk (jeremy murray) Subject: Re: Anyone knowledgeable about RecA? X-Accept-Language: en Message-ID: <36D7EF95.842F7029@bmb.leeds.ac.uk> NNTP-Posting-Host: bmbpc232.leeds.ac.uk X-Mailer: Mozilla 4.5 [en] (Win95; I) Content-Type: text/plain; charset=us-ascii Organization: Univ. of Leeds MIME-Version: 1.0 Date: Sat, 27 Feb 1999 13:14:08 +0000 (GMT) References: <01be5f86$6519d240$1c9c8e95@gradlab_pc_2.biomath.medsch.ucla.edu> To: Kevin Klapstein Lines: 45 Content-Transfer-Encoding: 7bit Hi Kevin I think the bast place to search for the answer to your questions is the 3D structure of proteins that catalyse the same type of reaction. I am not sure if the RecA structure has been solved yet, but there have been a couple of recent papers in which the structure of Holliday junction complexes have been solved. I think the Feb. edition of Nature Structural Biol had such a paper. You could also try a PDB search http://www2.ebi.ac.uk/pdb-bin/pdbmain have fun j Kevin Klapstein wrote: > Hello; > > I am a graduate student doing some work on RecA strand exchange > reactions. Unfortunately, my original background is not in biology > (it's in physics) so there are rather a lot of questions I have which > may be trivial background knowledge to somebody with a biology > background. > > I would greatly appreciate any help on some of these questions. > My email address is > > kklap@biomath.medsch.ucla.edu > > Two of my main questions are: > > 1) For a strand exchange reaction in which one of the substrates had a > heterologous insert is completed, is the heterologous region incorporated > into the final product as a loop (a D loop?) of ssDNA? > 2) During recombination events in prokaryotes where foreign DNA is > incorporated into the DNA of the organism, I assume that in the scenario > described above, the backbone of the DNA strand without the heterologous > insert would eventually be broken, and the heterologous region used as a > template for synthesis. This would lead to lengthening of the DNA over > time, with many recombination events. What are the biological implications > of this? (I know of several physical implications). > > Cheers, > > Kevin .