Bioinformatics, Biocomputing and Perl: An Introduction

485 Pages·2004·3.271 MB·English

by  Michael Moorhouse, Paul Barry

Bioinformatics
Biocomputing and
Perl
An Introduction to Bioinformatics
Computing Skills and Practice
Michael Moorhouse
Post-Doctoral Worker from Erasmus MC,
The Netherlands
Paul Barry
Department of Computing and Networking,
Institute of Technology,
Carlow, Ireland
Copyright2004 JohnWiley&SonsLtd,TheAtrium,SouthernGate,Chichester,
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Contents
Preface xv
1 Settingthe Biological Scene 1
1.1 IntroducingBiologicalSequenceAnalysis 1
1.2 ProteinandPolypeptides 4
1.3 GeneralisedModelsandtheirUse 5
1.4 TheCentralDogmaofMolecularBiology 6
1.4.1 Transcription 6
1.4.2 Translation 7
1.5 GenomeSequencing 10
1.5.1 Sequenceassembly 11
1.6 TheExampleDNA-gene-proteinsystemwewilluse 12
WheretofromHere 13
2 Settingthe Technological Scene 15
2.1 TheLayersofTechnology 15
2.1.1 Frompassiveusertoactivedeveloper 16
2.2 Findingperl 17
2.2.1 Checkingforperl 17
WheretofromHere 18
I Working with Perl 19
3 TheBasics 21
3.1 Let’sGetStarted! 21
3.1.1 RunningPerlprograms 22
3.1.2 Syntaxandsemantics 23
3.1.3 Program:runthyself! 25
3.2 Iteration 26
3.2.1 UsingthePerlwhileconstruct 26
3.3 MoreIterations 30
3.3.1 Introducingvariablecontainers 31
3.3.2 Variablecontainersandloops 32
viii Contents
3.4 Selection 34
3.4.1 UsingthePerlifconstruct 35
3.5 ThereReallyisMTOWTDI 36
3.6 ProcessingDataFiles 41
3.6.1 Askinggetlinestodomore 43
3.7 IntroducingPatterns 44
WheretofromHere 46
TheMaximsRepeated 46
4 PlacestoPutThings 49
4.1 BeyondScalars 49
4.2 Arrays:AssociatingDatawithNumbers 49
4.2.1 Workingwitharrayelements 51
4.2.2 Howbigisthearray? 51
4.2.3 Addingelementstoanarray 52
4.2.4 Removingelementsfromanarray 54
4.2.5 Slicingarrays 54
4.2.6 Pushing,popping,shiftingandunshifting 56
4.2.7 Processingeveryelementinanarray 57
4.2.8 Makinglistseasiertoworkwith 59
4.3 Hashes:AssociatingDatawithWords 60
4.3.1 Workingwithhashentries 61
4.3.2 Howbigisthehash? 61
4.3.3 Addingentriestoahash 62
4.3.4 Removingentriesfromahash 62
4.3.5 Slicinghashes 63
4.3.6 Workingwithhashentries:acompleteexample 64
4.3.7 Processingeveryentryinahash 66
WheretofromHere 68
TheMaximsRepeated 68
5 Getting Organised 71
5.1 NamedBlocks 71
5.2 IntroducingSubroutines 73
5.2.1 Callingsubroutines 73
5.3 CreatingSubroutines 74
5.3.1 Processingparameters 76
5.3.2 Betterprocessingofparameters 78
5.3.3 Evenbetterprocessingofparameters 80
5.3.4 Amoreflexibledrawlinesubroutine 83
5.3.5 Returningresults 84
5.4 VisibilityandScope 85
5.4.1 Usingprivatevariables 86
5.4.2 Usingglobalvariablesproperly 88
5.4.3 Thefinalversionofdrawline 89
5.5 In-builtSubroutines 90
5.6 GroupingandReusingSubroutines 92
5.6.1 Modules 93
5.7 TheStandardModules 96
5.8 CPAN:TheModuleRepository 96
5.8.1 SearchingCPAN 97
5.8.2 InstallingaCPANmodulemanually 98
Contents ix
5.8.3 InstallingaCPANmoduleautomatically 99
5.8.4 AfinalwordonCPANmodules 99
WheretofromHere 100
TheMaximsRepeated 100
6 AboutFiles 103
6.1 I/O:InputandOutput 103
6.1.1 Thestandardstreams:STDIN,STDOUTandSTDERR 103
6.2 ReadingFiles 105
6.2.1 Determiningthedisk-filenames 106
6.2.2 Openingthenameddisk-files 108
6.2.3 Readingalinefromeachofthedisk-files 110
6.2.4 Puttingitalltogether 110
6.2.5 Slurping 114
6.3 WritingFiles 116
6.3.1 Redirectingoutput 117
6.3.2 Variableinterpolation 117
6.4 ChoppingandChomping 118
WheretofromHere 119
TheMaximsRepeated 119
7 Patterns,PatternsandMorePatterns 121
7.1 PatternBasics 121
7.1.1 Whatisaregularexpression? 122
7.1.2 Whatmakesregularexpressionssospecial? 122
7.2 IntroducingthePatternMetacharacters 124
7.2.1 The+repetitionmetacharacter 124
7.2.2 The|alternationmetacharacter 126
7.2.3 Metacharactershorthandandcharacterclasses 127
7.2.4 Moremetacharactershorthand 128
7.2.5 Morerepetition 130
7.2.6 The?and*optionalmetacharacters 130
7.2.7 Theanycharactermetacharacter 131
7.3 Anchors 132
7.3.1 The\bwordboundarymetacharacter 132
7.3.2 The^start-of-linemetacharacter 133
7.3.3 The$end-of-linemetacharacter 133
7.4 TheBindingOperators 134
7.5 RememberingWhatWasMatched 135
7.6 GreedybyDefault 137
7.7 AlternativePatternDelimiters 138
7.8 AnotherUsefulUtility 139
7.9 Substitutions:SearchandReplace 140
7.9.1 Substitutingforwhitespace 141
7.10 FindingaSequence 142
WheretofromHere 146
TheMaximsRepeated 146
8 PerlGrabbag 147
8.1 Introduction 147
8.2 Strictness 147
x Contents
8.3 PerlOne-liners 149
8.4 RunningOtherProgramsfromperl 152
8.5 RecoveringfromErrors 153
8.6 Sorting 155
8.7 HEREDocuments 159
WheretofromHere 160
TheMaximsRepeated 161
II Working with Data 163
9 Downloading Datasets 165
9.1 Let’sGetData 165
9.2 DownloadingfromtheWeb 165
9.2.1 UsingwgettodownloadPDBdata-files 167
9.2.2 Mirroringadataset 168
9.2.3 Smartermirroring 168
9.2.4 Downloadingasubsetofadataset 169
WheretofromHere 171
TheMaximsRepeated 171
10 TheProteinDatabank 173
10.1 Introduction 173
10.2 DeterminingBiomoleculeStructures 174
10.2.1 X-RayCrystallography 174
10.2.2 Nuclearmagneticresonance 176
10.2.3 Summaryofproteinstructuremethods 177
10.3 TheProteinDatabank 177
10.4 ThePDBData-fileFormats 179
10.4.1 Examplestructures 180
10.4.2 DownloadingPDBdata-files 181
10.5 AccessingDatainPDBEntries 182
10.6 AccessingPDBAnnotationData 183
10.6.1 FreeRandresolution 184
10.6.2 Databasecrossreferences 186
10.6.3 Coordinatessection 188
10.6.4 Extracting3Dcoordinatedata 191
10.7 ContactMaps 192
10.8 STRIDE:SecondaryStructureAssignment 196
10.8.1 InstallationofSTRIDE 197
10.9 AssigningSecondaryStructures 197
10.9.1 UsingSTRIDEandparsingtheoutput 200
10.9.2 ExtractingaminoacidsequencesusingSTRIDE 204
10.10 IntroducingthemmCIFProteinFormat 205
10.10.1ConvertingmmCIFtoPDB 206
10.10.2ConvertingmmCIFstoPDBwithCIFTr 206
10.10.3ProblemswiththeCIFTrconversion 208
10.10.4SomeadviceonusingmmCIF 208
10.10.5AutomatedconversionofmmCIFtoPDB 208
WheretofromHere 210
TheMaximsRepeated 210
Contents xi
11 Non-redundantDatasets 211
11.1 IntroducingNon-redundantDatasets 211
11.1.1 Reasonsforredundancy 211
11.1.2 Reductionofredundancy 212
11.1.3 Non-redundancyandnon-representative 212
11.2 Non-redundantProteinStructures 213
WheretofromHere 217
TheMaximsRepeated 217
12 Databases 219
12.1 IntroducingDatabases 219
12.1.1 Relatingtables 220
12.1.2 Theproblemwithsingle-tabledatabases 222
12.1.3 Solvingtheone-tableproblem 222
12.1.4 Databasesystem:adefinition 224
12.2 AvailableDatabaseSystems 224
12.2.1 Personaldatabasesystems 225
12.2.2 Enterprisedatabasesystems 225
12.2.3 Opensourcedatabasesystems 225
12.3 SQL:theLanguageofDatabases 226
12.3.1 DefiningdatawithSQL 226
12.3.2 ManipulatingdatawithSQL 227
12.4 ADatabaseCaseStudy:MER 227
12.4.1 TherequirementfortheMERdatabase 231
12.4.2 Installingadatabasesystem 232
12.4.3 CreatingtheMERdatabase 233
12.4.4 AddingtablestotheMERdatabase 235
12.4.5 PreparingSWISS-PROTdataforimportation 238
12.4.6 Importingtab-delimiteddataintoproteins 245
12.4.7 Workingwiththedatainproteins 246
12.4.8 AddinganothertabletotheMERdatabase 248
12.4.9 PreparingEMBLdataforimportation 249
12.4.10Importingtab-delimiteddataintodnas 253
12.4.11Workingwiththedataindnas 253
12.4.12Relatingdatainonetabletothatinanother 254
12.4.13AddingthecrossrefstabletotheMERdatabase 255
12.4.14Preparingcrossreferencesforimportation 256
12.4.15Importingtab-delimiteddataintocrossrefs 259
12.4.16Workingwiththedataincrossrefs 259
12.4.17AddingthecitationstabletotheMERdatabase 263
12.4.18Preparingcitationinformationforimportation 265
12.4.19Importingtab-delimiteddataintocitations 268
12.4.20Workingwiththedataincitations 268
WheretofromHere 269
TheMaximsRepeated 269
13 DatabasesandPerl 273
13.1 WhyProgramDatabases? 273
13.2 PerlDatabaseTechnologies 274
13.3 PreparingPerl 275
13.3.1 CheckingtheDBIinstallation 275
xii Contents
13.4 ProgrammingDatabaseswithDBI 276
13.4.1 Developingadatabaseutilitymodule 279
13.4.2 Improvingupondumpresults 280
13.5 CustomisingOutput 282
13.6 CustomisingInput 285
13.7 ExtendingSQL 289
WheretofromHere 292
TheMaximsRepeated 292
III Working with the Web 295
14 TheSequenceRetrievalSystem 297
14.1 AnExampleofWhat’sPossible 297
14.2 WhySRS? 298
14.3 UsingSRS 298
WheretofromHere 300
TheMaximsRepeated 300
15 WebTechnologies 303
15.1 TheWebDevelopmentInfrastructure 303
15.2 CreatingContentfortheWWW 305
15.2.1 ThestaticcreationofWWWcontent 308
15.2.2 ThedynamiccreationofWWWcontent 308
15.3 PreparingApacheforPerl 310
15.3.1 Testingtheexecutionofserver-sideprograms 312
15.4 SendingDatatoaWebServer 315
15.5 WebDatabases 320
WheretofromHere 327
TheMaximsRepeated 327
16 WebAutomation 329
16.1 WhyAutomateSurfing? 329
16.2 AutomatedSurfingwithPerl 330
WheretofromHere 335
TheMaximsRepeated 336
IV Working with Applications 337
17 Tools andDatasets 339
17.1 Introduction 339
17.2 SequenceDatabases 340
17.2.1 UnderstandingEMBLentries 343
17.2.2 UnderstandingSWISS-PROTentries 346
17.2.3 Summarisingsequencesdatabases 347
17.3 GeneralConceptsandMethods 347
17.3.1 Predictionsandvalidation 348
17.3.2 True/False/Negative/Positive 348
Contents xiii
17.3.3 Balancingtheerrors 351
17.3.4 Usingmultiplealgorithmstoimproveperformance 352
17.3.5 tRNA-ScanSE,acasestudy 353
17.4 IntroducingBioinformaticsTools 357
17.4.1 ClustalW 358
17.4.2 Algorithmsandmethods 359
17.4.3 Installationanduse 360
17.4.4 Substitution/scoringmatrices 361
17.5 BLAST 362
17.5.1 InstallingNCBI-BLAST 364
17.5.2 Preparationofdatabasefilesforfastersearching 365
17.5.3 ThedifferenttypesofBLASTsearch 369
17.5.4 FinalwordsonBLAST 371
WheretofromHere 371
TheMaximsRepeated 371
18 Applications 373
18.1 Introduction 373
18.2 ScientificBackgroundtoMerOperon 374
18.2.1 Function 374
18.2.2 Geneticstructureandregulation 374
18.2.3 MobilityoftheMerOperon 375
18.3 DownloadingtheRawDNASequence 377
18.4 InitialBLASTSequenceSimilaritySearch 378
18.5 GeneMark 380
18.5.1 UsingBLASTtoidentifyspecificsequences 382
18.5.2 Dealingwithfalsenegativesandmissingproteins 386
18.5.3 Over-predictedgenesandfalsepositives 387
18.5.4 SummaryofvalidationofGeneMarkprediction 388
18.6 StructuralPredictionwithSWISS-MODEL 388
18.6.1 Alternativestohomologymodelling 390
18.6.2 ModellingwithSWISS-MODEL 390
18.7 DeepViewasaStructuralAlignmentTool 396
18.8 PROSITEandSequenceMotifs 401
18.8.1 UsingPROSITEpatternsandmatrices 402
18.8.2 DownloadingPROSITEanditssearchtools 403
18.8.3 FinalwordonPROSITE 407
18.9 Phylogenetics 407
18.9.1 AlookattheHMAdomainofMerAandMerP 407
WheretofromHere? 410
TheMaximsRepeated 411
19 DataVisualisation 413
19.1 IntroducingVisualisation 413
19.2 DisplayingTabularDataUsingHTML 415
19.2.1 DisplayingSWISS-PROTidentifiers 417
19.3 CreatingHigh-qualityGraphicswithGD 422
19.3.1 UsingtheGDmodule 424
19.3.2 DisplayinggenesinEMBLentries 426
19.3.3 Introducingmogrify 429