This is the C-terminal domain of ISP3 protein, which plays a role in asexual daughter cell formation, for example in T.gondii. The domain consists of a seven-stranded antiparallel beta-sandwich bordered on one end by a interstrand loop (open end) and ...
This is the C-terminal domain of ISP3 protein, which plays a role in asexual daughter cell formation, for example in T.gondii. The domain consists of a seven-stranded antiparallel beta-sandwich bordered on one end by a interstrand loop (open end) and capped at the other end by an amphipathic C-terminal helix (closed end). The loop between beta 5 and beta 6 is extended and variable. The domain adopts a pleckstrin homology (PH) fold, despite having neglible sequence similarity. PH domains are often found in proteins that support protein-lipid and play a role in mediating membrane localization through IP binding. However, the Phospholipid Binding Properties of PH domains is not conserved in the ISP3. Unlike PH domains, ISP3 is cysteine rich. The cysteine-rich nature of the ISP3s and the number of surface-exposed cysteines may result in redox instability and may also facilitate higher order multimerization. There are no disulfide bonds in ISP3 unlike in ISP1. It is worth noting that ISP1 and ISP3 share low sequence identity but contain the same secondary core elements [1].
