Phosphatidylinositol 3-Kinase Class III
PI 3-kinase Class III secondary structure
PI3K class III is a kinase protein and thus its structure is strongly associated with the function. The primary structure of this protein, which is the aminoacid sequence for the protein, consists of 887 aminoacids for the human and mouse PI3K class III catalytic subunit and 875 in yeast Saccharomyces cerevisiae. The secondary structure for PI3K class III from Drosophila melanogaster (Figure 1).This diagram includes DSSP secondary structure view as well as the PFAM domain alignment from sequence information. The diagram, however, shows only the 696 residues closer to the end of the protein.
Figure 1. Sequence and secondary structure of Drosophila melanogaster PI3K Class III. The diagram shows PFAM domain alligment (PDB ID 2X6H) [1].
The second diagram represents the human PI3K class III secondary structure (Figure 2) and it shows only DSSP secondary structure as PFAM is unavailable for this structure. This structure also contains incomplete number of aminoacids as only residues from 282 to 879 are present. However, tertiary and quaternary structures need to be considered to grasp the three-dimensional features of the proteins.
Figure 2. Sequence and secondary structure of human PI3K Class III. Figure does not contain domain allignments due to lack of information (PDB ID 3IHY) [2].
References:
1. Miller, S., Tavshanjian, B., Oleksy, A., Perisic, O., Houseman, B.T., Shokat, K.M. & Williams, R.L. 2010. Shaping Development of Autophagy Inhibitors with the Structure of the Lipid Kinase Vps34. Science, 327, 1638-null, http://www.rcsb.org/pdb/explore/remediatedSequence.do?structureId=2X6H&bionumber=1
2. Siponen, M.I., Tresaugues, L., Arrowsmith, C.H., Berglund, H., Bountra, C., Collins, R., Edwards, A.M., Flodin, S., Flores, A., Graslund, S., Hammarstrom, M., Johansson, A., Johansson, I., Karlberg, T., Kotenyova, T., Kotzsch, A., Kragh Nielsen, T., Moche, M., Nyman, T., Persson, C., Roos A.K., Sagemark, J., Schueler, H., Schutz, P., Thorsell, A.G., Van Den Berg, S., Weigelt, J., Welin, M., Wisniewska, M. & Nordlund, P. 2009. Human PIK3C3 crystal structure. TO BE PUBLISHED, null-null, http://www.rcsb.org/pdb/explore/remediatedSequence.do?structureId=3IHY&bionumber=1