title: Identification, expression, and purification of a unique stable domain from human HSPC144 protein.
abstract: 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 (15)N and (15)N/(13)C-labeled DUF589 domain samples have been prepared successfully and determination of the NMR structure is in progress.
authors.affiliation: Key Laboratory of Proteomics, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences.
authors.forename: Ai-Xin
authors.initials: AX
authors.lastname: Song
authors.forename: Yong-Gang
authors.initials: YG
authors.lastname: Chang
authors.forename: Yong-Guang
authors.initials: YG
authors.lastname: Gao
authors.forename: Xiao-Jing
authors.initials: XJ
authors.lastname: Lin
authors.forename: Yan-Hong
authors.initials: YH
authors.lastname: Shi
authors.forename: Dong-Hai
authors.initials: DH
authors.lastname: Lin
authors.forename: Qiu-Hua
authors.initials: QH
authors.lastname: Hang
authors.forename: Hong-Yu
authors.initials: HY
authors.lastname: Hu
mesh_terms: D000595:Amino Acid Sequence; D002850:Chromatography, Gel; D002942:Circular Dichroism; D019286:Endopeptidase K / Q000737:chemistry; D004926:Escherichia coli / Q000235:genetics; D015870:Gene Expression / Q000235:genetics*; D006801:Humans; D008969:Molecular Sequence Data; D008970:Molecular Weight; D019906:Nuclear Magnetic Resonance, Biomolecular; D009687:Nuclear Proteins / Q000737:chemistry / Q000235:genetics* / Q000302:isolation & purification; D010446:Peptide Fragments / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification; D017433:Protein Structure, Secondary; D011994:Recombinant Proteins / Q000096:biosynthesis* / Q000737:chemistry / Q000302:isolation & purification; D017386:Sequence Homology, Amino Acid; D021241:Spectrometry, Mass, Electrospray Ionization
chemical_list: D009687:Nuclear Proteins; D010446:Peptide Fragments; D011994:Recombinant Proteins; C505706:THYN1 protein, human; D019286:Endopeptidase K