1IJ6

CA2+-BOUND STRUCTURE OF MULTIDOMAIN EF-HAND PROTEIN, CBP40, FROM TRUE SLIME MOLD

Summary for 1IJ6

• Entry DOI: 10.2210/pdb1ij6/pdb
• Related: 1IJ5
• Descriptor: PLASMODIAL SPECIFIC LAV1-2 PROTEIN, CALCIUM ION (2 entities in total)
• Functional Keywords: fourty kda calcium binding protein, cbp40, metal binding protein
• Biological source: Physarum polycephalum
• Total number of polymer chains: 1
• Total formula weight: 37297.93

Authors

Iwasaki, W.,Sasaki, H.,Nakamura, A.,Kohama, K.,Tanokura, M. (deposition date: 2001-04-25, release date: 2003-02-11, Last modification date: 2024-03-13)

Primary citation

Iwasaki, W.,Sasaki, H.,Nakamura, A.,Kohama, K.,Tanokura, M.
Metal-Free and Ca(2+)-Bound Structures of a Multidomain EF-Hand Protein, CBP40, from the Lower Eukaryote Physarum polycephalum
Structure, 11:75-85, 2003

PubMed Abstract: Acellular slime mold, Physarum polycephalum, has a unique wound-healing system. When cytoplasm of plasmodia is exposed to extracellular fluid, calcium binding protein 40 (CBP40) seals damaged areas, forming large aggregates Ca(2+) dependently. Part of the CBP40 is truncated at the N terminus by a proteinase in plasmodia (CBP40delta), which does not aggregate in the Ca(2+)-bound form. Here we report the crystal structures of CBP40delta in both the metal-free and the Ca(2+)-bound states. Both structures consist of three domains: coiled-coil, intervening, and EF-hand. The topology of the EF-hand domain is similar to that of calpain. The N-terminal half of CBP40Delta interacts with the C-terminal EF-hands through a large hydrophobic interface, necessary for high Ca(2+) affinity. Conformational change upon Ca(2+) binding is small; however, the structure of CBP40delta provides novel insights into the mechanism of Ca(2+)-dependent oligomerization.

PubMed: 12517342
DOI: 10.1016/S0969-2126(02)00932-2

Experimental method

X-RAY DIFFRACTION (3.1 Å)