Path: utzoo!utgpu!watserv1!watmath!uunet!tut.cis.ohio-state.edu!magnus.ircc.ohio-state.edu!csn!boulder!eesnyder From: eesnyder@boulder.Colorado.EDU (Eric E. Snyder) Newsgroups: bionet.general Subject: Re: restriction enzyme sites in mammalian cell Message-ID: Date: 23 Feb 91 20:43:13 GMT References: <9102230959.AA03533@genbank.bio.net> Sender: news@csn.org (news) Organization: Colorado SuperNet Inc. Lines: 43 Nntp-Posting-Host: beagle.colorado.edu BIOCOL@UNIPAD.UNIPD.IT writes: >In BioNews Thomas Collet says: >>Does anyone have a compilation of the cutting >>frequencies of restriction enzymes in immunoglobulin genes (or >>maybe just mammalian genes in general ?) Or maybe a literature >>reference ? >>Thanks >I think you can try by yourself using stochastic computer methods (as I did), >for example RND in BASIC. The frequence of cutting for each enzyme must be >1/4 exp n for each class with n bases of recogniction. A better way to estimate the cutting frequency is to adjust for genomic nucleotide composition. For instance, in AT rich genomes, restriction enzymes that have AT rich recognition sequences will cut more frequently that estimated by (.25)^n, where n is the length of the recognition sequence. For example, A = .30 T = .30 C = .20 G = .20 GAATTC = (.2)(.3)(.3)(.3)(.3)(.2) = 3.24x10^-4 vs. A = C = G = T = .25 GAATTC = .25^6 = 2.44x10^-4 --------------------------------------------------------------------------- TTGATTGCTAAACACTGGGCGGCGAATCAGGGTTGGGATCTGAACAAAGACGGTCAGATTCAGTTCGTACTGCTG Eric E. Snyder Department of MCD Biology We are not suspicious enough University of Colorado, Boulder of words, and calamity strikes. Boulder, Colorado 80309-0347 LeuIleAlaLysHisTrpAlaAlaAsnGlnGlyTrpAspLeuAsnLysAspGlyGlnIleGlnPheValLeuLeu --------------------------------------------------------------------------- Brought to you by Super Global Mega Corp .com