Lecture 2.21 Retrieving Information: Using Entrez

Lecture 2.22 Retrieving information: how it works: Servers have the records you want You need to understand the data they have, and how it is organized There are often many ways to get to an answer. Route to get there is not always obvious, but you need to think of alternatives and traps. Use some query language – each system has its own. Retrieve data in a specified format. Save it in a way that will be useful to you.

Lecture 2.23 What you may be looking for: Did a BLAST search – and you need more info about some of the proteins they found similarities to. Heard on about a disease gene that was recently discovered, and you want to know more about it. Want to build a dataset for local blast searches. A colleague wants you to do an alignment of all sequences from a given protein family.

Lecture 2.24 What you are looking for: PubMed paper from author X Sequence from gene X in organism Y All information about organelle W in model organism Y All information about disease X in human Orthologs of that disease genes in other model organisms

Lecture 2.25 Central Dogma: NCBI version RNA protein DNA Write a paper about it

Lecture 2.26 Entrez: Pathway to Discovery Amino acid sequence similarity Coding region features Nucleotide sequence similarity Term frequency statistics Literature citations in sequence databases MEDLINE abstracts Nucleotide sequences Protein sequences 1993

Lecture 2.27 Related Articles Type in your last name and find a paper form one of your teammates

Lecture 2.28 Hard link DNA to protein L12345

Lecture 2.29 From Fig 1 of Entrez search and retrieval system Jim Ostell Chapter 14, the NCBI Handbook. 2003

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Lecture Ctrl-F

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Lecture Getting started in Entrez

Lecture “ouellette bf” [au] AND yeast

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Lecture MeSH: Medical Subject Heading

Lecture A query Word : too many hits –More words (the Boolean ‘AND’ is the default) –Limit query to specified field –Limit query in time –Do Boolean on queries #1 AND #2 #3 NOT #5 #7 OR #8

Lecture hieter p [au]

Lecture Limit in Time:

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Lecture No abstract With abstract Full Text on-line Full Text in PubMed Central

Lecture boguski m [au] 99 boguski ms [au] 80

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Lecture Other types of links in Entrez Next slides to explore other kind of things linked into Entrez records.

Lecture “hieter p” [au] cdc16p

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Lecture “Books”

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Lecture Link to Genome View of Chromosome I

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Lecture RefSeq RefSeq represents the NCBI curated “reference sequences” for all ‘worked’ genome. Historically, these used to be referred to as “GenBank-Gold”. RefSeq are either genomic, mRNA or protein sequences. Not all sequences are in RefSeq All RefSeq sequences are assembled/taken from things in GenBank.

Lecture Some of the features of the RefSeq: non-redundancy explicitly linked nucleotide and protein sequences updates to reflect current knowledge of sequence data and biology data validation and format consistency distinct accession series ongoing curation by NCBI staff and collaborators, with review status indicated on each record

Lecture Accession number space GenBank: –1+5 (L12345, U00001) –2+6 (AF000001, AC000003) –4+2+6 (WGS) All have accession.version Protein: –1+5 (SwissProt/UniProt) –3+5 (GenPept) All have accession.version RefSeq: –N*_12345

Lecture RefSeq Accession Number Space NC_123456GenomicComplete genomic molecules including genomes, chromosomes, organelles, plasmids. NG_123456GenomicIncomplete genomic region; supplied to support the NCBI Genome Annotation pipeline. NM_123456mRNA NR_123456RNANon-coding transcripts including structural RNAs, transcribed pseudogenes, and others NP_123456Protein NP_ ProteinPlanned expansion of accession series

Lecture Automated Assemblies NT_123456GenomicIntermediate genomic assemblies of BAC sequence data NW_123456GenomicIntermediate genomic assemblies of Whole Genome Shotgun sequence data

Lecture Model RefSeq records XM_123456mRNAmodel mRNA provided by the Genome Annotation process; sequence corresponds to the genomic contig. XR_123456RNAmodel non-coding transcripts provided by the Genome Annotation process; sequence corresponds to the genomic contig. XP_123456Proteinmodel proteins provided by the Genome Annotation process; sequence corresponds to the genomic contig.

Lecture WGS special case NZ_ABCD GenomicA collection of whole genome shotgun sequence data for a project. Accessions are not tracked between releases. The first four characters following the underscore (e.g. 'ABCD') identifies a genome project. ZP_ ProteinProteins annotated on NZ_ accessions (often via computational methods).

Lecture Download all the data Entrez and RefSeq

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Lecture Locus Link

Lecture Things to watch out for:

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