3UL6

Saccharum officinarum canecystatin-1 in space group P6422

Summary for 3UL6

• Entry DOI: 10.2210/pdb3ul6/pdb
• Related: 3UL5
• Descriptor: Canecystatin-1, 2-{2-[2-(2-{2-[2-(2-ETHOXY-ETHOXY)-ETHOXY]-ETHOXY}-ETHOXY)-ETHOXY]-ETHOXY}-ETHANOL (3 entities in total)
• Functional Keywords: cystatin, defense, hydrolase inhibitor
• Biological source: Saccharum officinarum (noble cane,sugarcane)
• Total number of polymer chains: 2
• Total formula weight: 31089.16

Authors

Valadares, N.F.,Pereira, H.M.,Oliveira-Silva, R.,Garratt, R.C. (deposition date: 2011-11-10, release date: 2012-12-12, Last modification date: 2024-02-28)

Primary citation

Valadares, N.F.,de Oliveira-Silva, R.,Cavini, I.A.,Marques, I.A.,Pereira, H.D.,Soares-Costa, A.,Henrique-Silva, F.,Kalbitzer, H.R.,Munte, C.E.,Garratt, R.C.
X-ray crystallography and NMR studies of domain-swapped canecystatin-1.
Febs J., 280:1028-1038, 2013

PubMed Abstract: The three-dimensional structure of canecystatin-1, a potent inhibitor of cysteine proteases from sugarcane (Saccharum officinarum), has been solved in two different crystal forms. In both cases, it is seen to exist as a domain-swapped dimer, the first such observation for a cystatin of plant origin. Size exclusion chromatography and multidimensional NMR spectroscopy show the dimer to be the dominant species in solution, despite the presence of a measurable quantity of monomer undergoing slow exchange. The latter is believed to be the active species, whereas the domain-swapped dimer is presumably inactive, as its first inhibitory loop has been extended to form part of a long β-strand that forms a double-helical coiled coil with its partner from the other monomer. A similar structure is observed in human cystatin C, but the spatial disposition of the two lobes of the dimer is rather different. Dimerization is presumably a mechanism by which canecystatin-1 can be kept inactive within the plant, avoiding the inhibition of endogenous proteases. The structure described here provides a platform for the rational design of specific cysteine protease inhibitors for biotechnological applications.

PubMed: 23241243
DOI: 10.1111/febs.12095

Experimental method

X-RAY DIFFRACTION (2.63 Å)