Publication Abstract from PubMed
The crystal structure of the unbound form of HIV-1 subtype A protease (PR) has been determined to 1.7 A resolution and refined as a homodimer in the hexagonal space group P6(1) to an R(cryst) of 20.5%. The structure is similar in overall shape and fold to the previously determined subtype B, C and F PRs. The major differences lie in the conformation of the flap region. The flaps in the crystal structures of the unbound subtype B and C PRs, which were crystallized in tetragonal space groups, are either semi-open or wide open. In the present structure of subtype A PR the flaps are found in the closed position, a conformation that would be more anticipated in the structure of HIV protease complexed with an inhibitor. The amino-acid differences between the subtypes and their respective crystal space groups are discussed in terms of the differences in the flap conformations.
Structure of the unbound form of HIV-1 subtype A protease: comparison with unbound forms of proteases from other HIV subtypes.,Robbins AH, Coman RM, Bracho-Sanchez E, Fernandez MA, Gilliland CT, Li M, Agbandje-McKenna M, Wlodawer A, Dunn BM, McKenna R Acta Crystallogr D Biol Crystallogr. 2010 Mar;66(Pt 3):233-42. Epub 2010 Feb 12. PMID:20179334[1]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.