3etn

Protein Summary

The sequence of this protein matches SIS domain of PFAM family PF01380 (http://pfam.sanger.ac.uk/family?acc=PF01380). The SIS domain seems to have a common function in phopshosugar isomerization (Bateman 1999). The structure of 391616 matches closely to 1vim (Z=20.7 rmsd 2.7A for 177 Ca with seqid 23%), 1m3s, 1jeo, 2i2w, 1x94, 1viv, 3bjz etc, most of them structural genomics targets.  The biological relevant oligomer is likely tetramer, as observed in the asymmetric unit. This is consistent with the active site arrangement since the C-terminus is required for forming the active site of a neighbour promoter. A CMK (cmp-2-keto-3-deoxy-octulosonic acid) molecule is present in the  active site of 391616, the CMK is idenitified by unambiguous density. The CMK appears to be an inhibitor of 391616 (?). It is similar to Leptospira interrogans polysialic acid capsule expression protein KpsF.

 Figure 1. CMK in experimental density (density modified, 1.5 sigma)

References

Bateman A; , Trends Biochem Sci 1999;24:94-95.: The SIS domain: a phosphosugar-binding domain. PUBMED:10203754

Teplyakov A, Obmolova G, Badet-Denisot MA, Badet B, Polikarpov I; , Structure 1998;6:1047-1055.: Involvement of the C terminus in intramolecular nitrogen channeling in glucosamine 6-phosphate synthase: evidence from a 1.6 A crystal structure of the isomerase domain. PUBMED:9739095

Martinez-Cruz, L.A.,  Dreyer, M.K.,  Boisvert, D.C.,  Yokota, H.,  Martinez-Chantar, M.L.,  Kim, R.,  Kim, S.H. (2002) Crystal structure of MJ1247 protein from M. jannaschii at 2.0 A resolution infers a molecular function of 3-hexulose-6-phosphate isomerase. Structure 10: 195-204

Ligand Summary