Triose phosphate isomerase (TIM) from the hyperthermophilic bacterium Thermotoga maritima crystallizes as a tetramer that appears to be a pair of dimers similar to those observed in crystals of other TIMs (Maes et al. 1999). The two dimers are joined by disulphide bonds between pairs of Cys142. As noticed by Gayathri et al.(2007) this linkage is not consistent with the dimer seen in crystals being the same as the dimer in solution and Gayathri et al. conclude that the "tetramerization appears to be a crystallization artifact."
However, when the TIM monomers are docked by the methods described in this blog, the pairs of Cys142 are naturally in close proximity. The native structure of TIM from T. maritima is now included in the Gallery. It can be seen that the disulfide bond is indeed a natural part of the quaternary structure and the form of dimer seen in crystals is the actual artifact.
1 comment:
Very interesting and changeling research work and hope outcomes are breakthrough of existing knowledge.
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