Protein Information Resource (PIR), National Biomedical Research Foundation, 3900 Reservoir Road NW, Washington, DC 20007, USA. Geetha@nbrf.georgetown.edu|Protein Information Resource (PIR), National Biomedical Research Foundation, 3900 Reservoir Road NW, Washington, DC 20007, USA. Geetha@nbrf.georgetown.edu|Protein Information Resource (PIR), National Biomedical Research Foundation, 3900 Reservoir Road NW, Washington, DC 20007, USA. Geetha@nbrf.georgetown.edu|Protein Information Resource (PIR), National Biomedical Research Foundation, 3900 Reservoir Road NW, Washington, DC 20007, USA. Geetha@nbrf.georgetown.edu|Protein Information Resource (PIR), National Biomedical Research Foundation, 3900 Reservoir Road NW, Washington, DC 20007, USA. Geetha@nbrf.georgetown.edu