蛋白质序列基础知识与打分矩阵VIP免费

序列比对(sequencealignment)retinol-bindingprotein(NP_006735)-lactoglobulin(P02754)中心思想：从随机的相似性中寻找同源导致的相似性1MKWVWALLLLAAWAAAERDCRVSSFRVKENFDKARFSGTWYAMAKKDPEG50RBP.||||.|...|:.||||.:|:1...MKCLLLALALTCGAQALIVT..QTMKGLDIQKVAGTWYSLAMAASD.44lactoglobulin51LFLQDNIVAEFSVDETGQMSATAKGRVR.LLNNWD..VCADMVGTFTDTE97RBP:||||::|.|.|||:|||.45ISLLDAQSAPLRV.YVEELKPTPEGDLEILLQKWENGECAQKKIIAEKTK93lactoglobulin98DPAKFKMKYWGVASFLQKGNDDHWIVDTDYDTYAV...........QYSC136RBP||||.|:.|||||..|94IPAVFKIDALNENKVL........VLDTDYKKYLLFCMENSAEPEQSLAC135lactoglobulin137RLLNLDGTCADSYSFVFSRDPNGLPPEAQKIVRQRQ.EELCLARQYRLIV185RBP.|||:||.||||136QCLVRTPEVDDEALEKFDKALKALPMHIRLSFNPTQLEEQCHI.......178lactoglobulin序列比对的基本概念Dayhoff模型和Blosum比对算法：局部比对和全局比对比对结果的统计检验序列比对的作用生物大分子的进化搜索相似序列ItisusedtoidentifydomainsormotifsthataresharedbetweenproteinsItisthebasisofdatabasesearching结构预测和基因预测蛋白质序列比对比DNA比对信息量更大•proteinismoreinformative(20vs4characters);manyaminoacidssharerelatedbiophysicalproperties•codonsaredegenerate:changesinthethirdpositionoftendonotaltertheaminoacidthatisspecified•proteinsequencesofferalonger“look-back”time•DNAsequencescanbetranslatedintoprotein,andthenusedinpairwisealignmentsQuery:181catcaactacaactccaaagacacccttacacccactaggatatcaacaaacctacccac240|||||||||||||||||||||||||||||||||||||||||||||||||||||||Sbjct:189catcaactgcaaccccaaagccacccct-cacccactaggatatcaacaaacctacccac247DNA比对的特殊作用•Manytimes,DNAalignmentsareappropriate--toconfirmtheidentityofacDNA--tostudynoncodingregionsofDNA--tostudyDNApolymorphisms--example:NeanderthalvsmodernhumanDNA序列比对的一些基本概念1MKWVWALLLLAAWAAAERDCRVSSFRVKENFDKARFSGTWYAMAKKDPEG50RBP.||||.|...|:.||||.:|:1...MKCLLLALALTCGAQALIVT..QTMKGLDIQKVAGTWYSLAMAASD.44lactoglobulin51LFLQDNIVAEFSVDETGQMSATAKGRVR.LLNNWD..VCADMVGTFTDTE97RBP:||||::|.|.|||:|||.45ISLLDAQSAPLRV.YVEELKPTPEGDLEILLQKWENGECAQKKIIAEKTK93lactoglobulin98DPAKFKMKYWGVASFLQKGNDDHWIVDTDYDTYAV...........QYSC136RBP||||.|:.|||||..|94IPAVFKIDALNENKVL........VLDTDYKKYLLFCMENSAEPEQSLAC135lactoglobulin137RLLNLDGTCADSYSFVFSRDPNGLPPEAQKIVRQRQ.EELCLARQYRLIV185RBP.|||:||.||||136QCLVRTPEVDDEALEKFDKALKALPMHIRLSFNPTQLEEQCHI.......178lactoglobulinPairwisealignmentofretinol-bindingproteinand-lactoglobulin1MKWVWALLLLAAWAAAERDCRVSSFRVKENFDKARFSGTWYAMAKKDPEG50RBP.||||.|...|:.||||.:|:1...MKCLLLALALTCGAQALIVT..QTMKGLDIQKVAGTWYSLAMAASD.44lactoglobulin51LFLQDNIVAEFSVDETGQMSATAKGRVR.LLNNWD..VCADMVGTFTDTE97RBP:||||::|.|.|||:|||.45ISLLDAQSAPLRV.YVEELKPTPEGDLEILLQKWENGECAQKKIIAEKTK93lactoglobulin98DPAKFKMKYWGVASFLQKGNDDHWIVDTDYDTYAV...........QYSC136RBP||||.|:.|||||..|94IPAVFKIDALNENKVL........VLDTDYKKYLLFCMENSAEPEQSLAC135lactoglobulin137RLLNLDGTCADSYSFVFSRDPNGLPPEAQKIVRQRQ.EELCLARQYRLIV185RBP.|||:||.||||136QCLVRTPEVDDEALEKFDKALKALPMHIRLSFNPTQLEEQCHI.......178lactoglobulinPairwisealignmentofretinol-bindingproteinand-lactoglobulinIdentity(bar)1MKWVWALLLLAAWAAAERDCRVSSFRVKENFDKARFSGTWYAMAKKDPEG50RBP.||||.|...|:.||||.:|:1...MKCLLLALALTCGAQALIVT..QTMKGLDIQKVAGTWYSLAMAASD.44lactoglobulin51LFLQDNIVAEFSVDETGQMSATAKGRVR.LLNNWD..VCADMVGTFTDTE97RBP:||||::|.|.|||:|||.45ISLLDAQSAPLRV.YVEELKPTPEGDLEILLQKWENGECAQKKIIAEKTK93lactoglobulin98DPAKFKMKYWGVASFLQKGNDDHWIVDTDYDTYAV...........QYSC136RBP||||.|:.|||||..|94IPAVFKIDALNENKVL.....