Valid protein characters for PHI-BLAST patterns:
ABCDEFGHIKLMNPQRSTVWXYZUValid DNA characters for PHI-BLAST patterns:
ACGTOther useful delimiters:
[ ] means any one of the characters enclosed in the brackets e.g., [LFYT] means one occurrence of L or F or Y or T - means nothing (this is a spacer character used by PROSITE) x with nothing following means any residue x(5) means 5 positions in which any residue is allowed (and similarly for any other single number in parentheses after x) x(2,4) means 2 to 4 positions where any residue is allowed, and similarly for any other two numbers separated by a comma; the first number should be < the second number. > can occur only at the end of a pattern and means nothing it may occur before a period (another spacer used by PROSITE) . may be used at the end of the pattern and means nothingWhen using the stand-alone program, the pattern should be in a file, with the first line starting:
IDfollowed by 2 spaces and a text string givign the pattern a name.
There should also be a line starting
PAfollowed by 2 spaces followed by the pattern description.
All other PROSITE codes in the first two columns are allowed, but only the HI code, described below is relevant to PHI-BLAST.
Here is an example from PROSITE.
ID CNMP_BINDING_2; PATTERN. AC PS00889; DT OCT-1993 (CREATED); OCT-1993 (DATA UPDATE); NOV-1995 (INFO UPDATE). DE Cyclic nucleotide-binding domain signature 2. PA [LIVMF]-G-E-x-[GAS]-[LIVM]-x(5,11)-R-[STAQ]-A-x-[LIVMA]-x-[STACV]. NR /RELEASE=32,49340; NR /TOTAL=57(36); /POSITIVE=57(36); /UNKNOWN=0(0); /FALSE_POS=0(0); NR /FALSE_NEG=1; /PARTIAL=1; CC /TAXO-RANGE=??EP?; /MAX-REPEAT=2;The line starting
IDgives the pattern a name. The lines starting
AC, DT, DE, NR, NR, CCare relevant to PROSITE users, but irrelevant to PHI-BLAST. These lines are tolerated, but ignored by PHI-BLAST.
The line starting
PA describes the pattern as: one of LIVMF followed by G followed by E followed by any single character followed by one of GAS followed by one of LIVM followed by any 5 to 11 characters followed by R followed by one of STAQ followed by A followed by any single character followed by one of LIVMA followed by any single character followed by one of STACVIn this case the pattern ends with a period. It can end with nothing after the last specifying symbol or any number of > signs or periods or combination thereof.
Here is another example, illustrating the use of an HI line.
ID ER_TARGET; PATTERN. PA [KRHQSA]-[DENQ]-E-L>. HI (19 22) HI (201 204)In this example, the HI lines specify that the pattern occurs twice, once from positions 19 through 22 in the sequence and once from positions 201 through 204 in the sequence. These specifications are relevant when stand-alone PHI-BLAST is used with the "seedp" option, in which the interesting occurrences of the pattern in the sequence are specified. In this case the HI lines specify which occurrence(s) of the pattern should be used to find good alignments.
In general, the seedp option is more useful than the standard patternp option ONLY when the pattern occurs K > 1 times in the sequence AND the user is interested in matching to J < K of those occurrences. Then using the HI lines enables the user to specify which occurrences are of interest.