Similarity between the sequences of retroviral capsids. Alignment of primate lentiviral capsid protein sequences demonstrates that they have conserved the proline rich Cyclophilin A binding loop on their outer surface. Glycine proline motifs are common (red arrow). Conserved prolines at the extremes of the loop are shown (black arrows). The alignment from which this selection was taken is available from the Los Alamos HIV sequences database . Retroviruses are named according to the species from which they were isolated. Genbank accession numbers are shown. Species abbreviations are as follows: cpz chimpanzee, deb De Brazza's monkey, den Dent's Mona monkey, drl drill, gsn greater spot nosed monkey, sm sooty mangabey, stm stump tailed macaque, mac rhesus macaque, lst L'Hoest monkey, mnd mandrill, mon Cercopithecus mona, mus Cercopithecus cephus, rcm red capped mangabey, gri African green monkey Grivet, sab African green monkey sabaeus, tan African green monkey tantalus, ver African green monkey vervet, sun sun tailed monkey, syk Sykes monkey.