FIGURE 4.

Usages of concepts c_0060 and c_0568. (A) Transparent surface rendering of the native human 20S proteasome at 1.8 Å (5le5), with the usage of concept c_0060 in the $\beta 5$ subunit (chain Y in the amino-acid region THR1 to ASN191) shown in cartoon. The closeup of this region reveals a chloride ion in all active sites. Chloride ions are known to facilitate a proton shuttle catalytic mechanism (Schrader et al., 2016). (B) Similar rendering as above for the usage of concept c_0568 in the 2.3 Å Ferredoxin structure from Mastigocladus laminosus (3p63 chain A in the amino acid region THR48 to GLU90). The closeup shows the region linked to the $\mathrm{F}{\mathrm{e}}_2{\mathrm{S}}_2$-cluster binding.