Analysis of bromodomain of BRD-7 gene and its prokaryotic expression.
OBJECTIVE
BRD-7 is a novel gene (AF: 152604), containing a bromodomain, was cloned in our lab. Previous studies showed that BRD-7 plays an obviously suppressive role on NPC cell growth. In order to clarify the function mechanism of this gene, we investigate an important motif of BRD-7, the bromodomain.


METHODS
The bromodomain of BRD-7 was analyzed by homology-based amino sequence and secondary structure analysis. In addition, we constructed a prokaryotic expression vector of bromodomain. Western blot analysis was used to confirm the expression of the bromodomain protein in Escherichia coli.


RESULTS
Homology-based sequence analysis revealed that the bromodomain of BRD-7 possibly contains four alpha helices (Z, A, B and C), and a hydrophobic pocket which is an important structure to recognize acetylated histone peptide. This bromodomain encoding a 12.8 kD protein, was introduced into Escherichia coli using the pGEX-4T-2 expression vector. After isopropyl beta-D-thiogalactopyranoside(IPTG) induction, a new anticipated protein of 38.8 kD appeared on SDS-PAGE and the result was confirmed by Western blot analysis.


CONCLUSIONS
BRD-7 of bromodomain protein is similar to three proteins containing known structural bromodomain motif by bio-informatics analysis, suggesting the bromodomain of BRD-7 should belong to co-activator subgroup and may have similar function that can selectively interact with acetylated histone peptide.
Peng
Cong
C
Cancer Research Institute, Xiang-Ya School of Medicine, Central South University, Changsha 410078, P. R. China.
Zhou
Ming
M
Zhang
Qiu-hong
QH
Tang
Ke
K
Li
Gui-yuan
GY
D000595:Amino Acid Sequence; D002868:Chromosomal Proteins, Non-Histone / Q000096:biosynthesis* / Q000737:chemistry / Q000235:genetics; D004926:Escherichia coli / Q000378:metabolism*; D015870:Gene Expression; D005822:Genetic Vectors; D006801:Humans; D009687:Nuclear Proteins / Q000096:biosynthesis* / Q000737:chemistry / Q000235:genetics; D017433:Protein Structure, Secondary; D011993:Recombinant Fusion Proteins / Q000096:biosynthesis / Q000235:genetics; D017386:Sequence Homology, Amino Acid; D000092468:Bromodomain Containing Proteins
D002868:Chromosomal Proteins, Non-Histone; D009687:Nuclear Proteins; D011993:Recombinant Fusion Proteins; C485694:BRD7 protein, human; D000092468:Bromodomain Containing Proteins