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-Linking -Subentries -Applications. Advanced SRS Course 12/12/02. Linking in SRS. Hyperlinks -links between entries which are displayed as hypertext -useful for examining entries that are referenced directly from entries Query links
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-Linking -Subentries -Applications Advanced SRS Course 12/12/02
Hyperlinks -links between entries which are displayed as hypertext -useful for examining entries that are referenced directly from entries Query links -allow you to construct queries using the relationships between databanks -require SRS to search through entries or indices in other databanks looking for matches Types of Links
EMBL PROSITE PDB PFAM InterPro BLOCKS Links between Databases SWISS-PROT
Direct link from ‘A’ to ‘B’ Direct link from ‘B’ to ‘C’ A B C Multistep link from ‘A’ to ‘C’ Advantages of SRS Linking Links are bi-directional
Two forms of the link page: -type you see if you initiate linking from either the query manager or the query result page -type you see if you initiate linking from an individual entry page The difference is at the top of these pages one provides a “find all entries” option, the other does not (see next 2 slides) The link page
In the selected databanks which are linked to the current query - this returns entries from other databanks which have links with entries in the current query In the current query which are linked to all selected databanks - this limits the query so that it includes only the entries(from the original query) which are linked to all of the selected databanks In the current query which are not linked to any of the selected databanks - this limits the query so that it includes only the entries(from the original query) which do not have links to the specified databanks Find all entries options
From an individual entry page No ‘find all entries’ options available
Can link from a single query or from multiple queries two ways to link your queries from the query manager page: - tick the checkbox that corresponds to a query set and click the LINK button - use the text box beside the Expression button Linking from query manager page
Useful alternative to using the linking pages Can be used to search for a link between two or more sets of results or between a set of results and a databank Expression linking
< entries in the set or databank to the left of the operator are returned if they have a link to any entries in the set or databank to the right of the operator > entries in the set or databank to the right of the operator are returned if they have a link to any entries in the set or databank to the left of the operator Linking operators
< Q1 < Q2 In Q1 that link to Q2 > Q1 > Q2 In Q2 that link to Q1 combined with logical operators: < & Q1<Q2 & Q3 In Q1 that link to Q2 &Q3 < | Q1<Q2 | Q3 In Q1 that link to Q2 or Q3 < ! Q1<Q2 ! Q3 In Q1 that link to Q2 but not Q3 Linking operations
A B A1 A2 A3 A4 A5 A6 B1 B2 B3 B4 B5 A > B is B2 B3 B4 (all entries in B that have links to A) A < B is A1 A2 A5 A6 (all entries in A that have links to B)
Necessary when there is repeated structured information within an entry Subentries DR EMBL; L44581; AAA99933.1; -. DR EMBL; L44582; AAA99934.1; -. DR EMBL; L44583; AAA99935.1; -. DR EMBL; L44584; AAA99936.1; -. DR EMBL; L44585; AAA99937.1; -. ….. FT DOMAIN 1 12 LUMENAL (POTENTIAL). FT TRANSMEM 13 33 POTENTIAL. FT DOMAIN 34 55 CYTOPLASMIC (POTENTIAL). FT TRANSMEM 56 76 POTENTIAL. FT DOMAIN 77 95 LUMENAL (POTENTIAL).
Search for entries containing one or more subentries with certain values and obtain a list of entry references Search for subentries with certain values and obtain a list of subentry references Use subentries to:
They are part of the entry and often require data from other fields in order for their meaning to be resolved and displayed Example: a SWISS-PROT feature requires part of the entry’s sequence to be displayed They can be regarded as databanks themselves and can be indexed and queried independently from the entries Example: search all the transmembrane segments with a given range of length Subentries have a double function:
Protein databases have 5 subentries: Reference Comment Links Feature Counter Nucleotide databases have 3 subentries: Reference Features Counters Subentries available
Some of the fields belonging to the subentries have a predetermined number of keys ( as specified by the database documentation). These fields have a controlled vocabulary and when you use the extended query forms you can select a value from a drop down menu. Examples are: CommentType DbName FtKey CountItem Controlled vocabularies
This is a special subentry created by SRS on the fly. It counts the number of times particular feature keys, comment types and links to a certain database occur within an entry It can be used to answer questions like: How many entries have 3 or more links to EMBL? How many entries have more than 8 disulphide bridges? How many entries have 2 or more comments about function? The Counter subentry
In the standard query form each subentry field name is preceded by the name of the subentry to which it belongs: Reference:authors Feature:FtKey Links:DbName The extended query form is divided up into sections. The top section contains the fields belonging to entry and below this are the subentries and the fields that they contain Subentry fields
Two types: Simple Links Parent Links Links with sets containing subentries
It is not possible to combine sets of entries with sets of subentries using the logical operators but link operators may be used between sets of entries and sets of subentries [swissprot-org:human] > [swissprot-ftkey:transmem] gives a set of transmembrane segment subentries found in human proteins [swissprot-org:human] < [swissprot-ftkey:transmem] returns all human entries that have a transmembrane segment Simple links
Sometimes it is necessary to do an explicit conversion from subentries to entries. This can be done using the operand parent. This method looks for links from the subentries to their respective parent entries and retrieves a set containing parent entries. [swissprot-ftkey:transmem] > parent gives the parent entries for the set of subentries from SWISS-PROT that have transmembrane sequence features Logical operators can then be used to combine the set of parent entries with another set of entries Parent Links
Types of entries Query Form
Using entry….. Feature that is 10 aa in length
Using feature….. Only returns transmem regions of exactly 10 aa
Sequence BLAST results - text file launch Run BLAST Indexing Upload user owned data BLAST query linking Pathway Prosite Applications in SRS SWISSPROT
Homology and similarity tools: BLASTP : database search tool FASTA : database search tool MPSrch Protein function analysis tools: PPSearh : BLASTProdom ScanRegExp FingerPrintScan PfScan InterProScan MPSrch Protein Applications in SRS • Sequence analysis tools: • - ClustalW
Homology and similarity tools BLASTN NFASTA FASTX FASTY Sequence analysis tools: NClustalW RestrictionMap Nucleotide applications in SRS