Acid proteases domain structures

The coagulation and anticoagulation proteases, factors VII, IX, and X, and protein C, have a common domain structure with an N-terminal gamma-carboxyglutamic acid (Gla)-containing domain that is followed by two EGF-like modules, whereas the C-terminal half of each protein is occupied by a trypsin-like serine protease domain. Prothrombin also has an N-terminal Gla domain and a C-terminal serine protease... 

The fold of the serine protease domain-type was described in Section V.C. SCP is more like o-lytic protease (Fujinaga et al, 1985) than a-chymotrypsin (Matthews et al, 1967), but with loops that are even shorter (Fig. 4 see Color Insert). Unlike the other proteases, there are no disulfide bonds. The structure of the C terminus is completely different from either of the other two proteases, and it leaves the final three amino acids in the active site. These superimpose on the structure of a peptide inhibitor determined as a complex with o-lytic protease (Bone et al, 1987). This indicates that the N-terminal product of the autocatalytic lysis of... 

The map was therefore reinterpreted for the revised positions of the molecular boundary near the helical segment. The molecular boundaries were also slightly changed in two other places where the separation of molecules was also not well defined on the map. After this modification, the entrance into the cavity became wider and the two-domain structure of the enzyme more prominent. The dimensions and the shape of the molecule became very similar to those of microbial acid protease (14). 

Fig. 6. Terminal capping and lateral bulging of globular domains in the //-solenoid of the hemoglobin protease from E. coli (Otto et al., 2005). The //-solenoid domains are shown in blue and the remaining regions in dark yellow. (A) Ribbon diagram of the 3D structure and (B) linear map of the domain distribution within the amino acid sequence.

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