Coding regions and mutated codons.

<p>Original codons are the most probable codons observed in control; mutated codons are those determined by nucleotide changes in X4 pseudotyped experiments, bold capital letters indicate base substitutions within affected codons, mutated amino acids are underlined; the 2 last columns indicate codons and amino acids at the same positions in the HIV-1 reference strain (NL4-3 GenBank accession number AF324493).</p><p>Coding regions and mutated codons.