Table 1. Proteins with knotted backbones.

protein family	pdb	chain start-stop	knot type	knotted core
RNA methytransferase (α/β knot)	1ns5	1–153	31	69–121
Carbonic anhydrase	1lug	2–260	31	31–257
SAM synthetase	1fug	1–383	31	33–260
Transcarbamylase fold	1js1	1–324	31	169–267
Zinc-finger fold	2k0a	−1–107	31	18–78
Ribbon-helix-helix superfamily	2efv	6–87	31	19–66
CII Ketol-acid reductoisomerase	1yve	83–595	41	321–533
Chromophore binding domain*	1ztu	5–325	41 *	41–298
Ubiquitin Hydrolase	2etl	1–223	52	10–216
α -haloacid dehalogenase I	3bjx	−14–296	61	71–268

For each fold an example pdb code is given. Chain start-stop refers to the first and the last amino acid, which are resolved in the structure. The knotted core is the minimum configuration which stays knotted after a series of deletions from either terminus as given by our web server [37]. This “knot size” is determined by an automated procedure [7],[37], and results should only be regarded as a guideline.

*: There are several missing (unresolved) amino acids in 1ztu – the complete structure will likely contain a figure-eight knot. Slipknots are not listed in this table, which (of course) also contain knots in their backbone.