|PROSITE documentation PDOC00015
Bipartite nuclear localization signal profile
The uptake of protein by the nucleus is extremely selective and nuclear
proteins must therefore contain within their final structure a signal that
specifies selective accumulation in the nucleus [1,2]. Studies on some nuclear
proteins, such as the large T antigen of SV40, have indicated which part of
the sequence is required for nuclear translocation. The known nuclear
targeting sequences are generally basic, but there seems to be no clear
common denominator between all the known sequences. Although some consensus
sequence patterns have been proposed (see for example ), the current best
strategy to detect a nuclear targeting sequence is based  on the following
definition of what is called a 'bipartite nuclear localization signal':
(1) Two adjacent basic amino acids (Arg or Lys).
(2) A spacer region of any 10 residues.
(3) At least three basic residues (Arg or Lys) in the five positions
after the spacer region.
The profile we developed covers the entire bipartite nuclear localization
This profile replace an obsolete rule. All the information in the rule
has been encoded in the profile format.
October 2006 / Text revised; profiles added; rule deleted.
PROSITE method (with tools and information) covered by this documentation:
|NLS_BP, PS50079; Bipartite nuclear localization signal profile (MATRIX with a high probability of occurrence!)
|Sequences known to belong to this class detected by the profile:
||56% of known nuclear proteins according to 
|Other sequence(s) detected in Swiss-Prot:
||about 4.2% of non-nuclear proteins according to .
||Garcia-Bustos J.F., Heitman J., Hall M.N.
||Biochim. Biophys. Acta 1071:83-101(1991).
||Gomez-Marquez J., Segade F.
||FEBS Lett. 226:217-219(1988).
||Dingwall C., Laskey R.A.
||Nuclear targeting sequences -- a consensus?
||Trends Biochem. Sci. 16:478-481(1991).
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