HSPC144 is a newly identified gene in human CD34+ hematopoietic stem/progenitor cells. In this work, we have expressed and purified the 225-residue protein from Escherichia coli BL21 (DE3) and identified a stable fragment HSPC144-P (residues 44-225) by limited proteolysis method. The HSPC144-P fragment exhibits high stability with a little increase of secondary structure percentage as compared with the full-length protein. We anticipated that the N-terminally truncated protein possesses a more compact structure. By sequence analysis, the proteolytic fragment shares a great similarity with DUF589 domain, a previously identified domain with unknown function. This novel domain is highly conserved in Thy28 proteins and is worthy of structural and functional studies. We have subcloned this homologous domain from HSPC144 protein and purified to homogeneity for structure analysis. The 15N and 15N/13C-labeled DUF589 domain samples have been prepared successfully and determination of the NMR structure is in progress.
Bibliographical noteFunding Information:
This work was supported by grants from the 863 Hi-Tech program (2002BA711A13), the Chinese Academy of Sciences (KSCX1-SW-17) and the Shanghai Commission of Science and Technology (03JC14081).
Copyright 2008 Elsevier B.V., All rights reserved.
- DUF589 domain
- HSPC protein
- Limited proteolysis
- NMR analysis