The index is rebuilt from the Protein Data Bank every week. This page shows every published version, what the most recent update added, and which protein families and organisms became reachable because of it.
On 28 October 2026 the admission floor moved from 250 to 175 daltons, with sugars, amino acids, nucleotides and metal-containing components below 250 daltons excluded. The ligands added in that version come from the rule change, not from that week's Protein Data Bank release.