Janke Carsten, Martin Davy, Giraud-Panis Marie-Josèphe, Decoville Martine, Locker Daniel
Centre de Biophysique Moléculaire, CNRS, conventionné avec l'Université d'Orléans, rue Charles Sadron, 45071 Orléans cedex 2, France.
J Biochem. 2003 Apr;133(4):533-9. doi: 10.1093/jb/mvg063.
The protein DSP1 belongs to the group of HMG-box proteins, which share the common structural feature of the HMG-box. This approximately 80 amino acid long motif binds DNA via the minor groove. DSP1 was discovered as a transcriptional co-repressor of Dorsal in Drosophila melanogaster and then was shown to participate to the remodeling of chromatin. By means of sequence alignment and gene organization, DSP1 was classified as the fly homologue of the vertebrate proteins HMGB1/2. DSP1 contains two HMG boxes flanked by two glutamine-rich domains at the N-terminus. In addition, the HMG domain of DSP1 displays two differences in its primary sequence as compared to the vertebrate HMGB1: a shorter acidic tail and a linker between the two boxes longer by 6 amino acids. By comparing several functional parameters of DSP1 with those of HMGB1, the present study establishes the functional equivalence of both proteins in terms of DNA recognition. The major structural difference between the two proteins, the glutamine-rich N-terminal tail of DSP1, which does not exist in HMGB1, did not interfere with any of the studied DNA-binding properties of the proteins.
蛋白质DSP1属于HMG框蛋白家族，该家族具有HMG框这一共同结构特征。这个约80个氨基酸长的基序通过小沟与DNA结合。DSP1最初是作为黑腹果蝇中Dorsal的转录共抑制因子被发现的，随后被证明参与染色质重塑。通过序列比对和基因结构分析，DSP1被归类为脊椎动物蛋白HMGB1/2的果蝇同源物。DSP1在N端包含两个HMG框，两侧是两个富含谷氨酰胺的结构域。此外，与脊椎动物HMGB1相比，DSP1的HMG结构域在其一级序列上有两个差异：酸性尾巴较短，两个框之间的连接区多6个氨基酸。通过比较DSP1和HMGB1的几个功能参数，本研究确定了两种蛋白在DNA识别方面的功能等效性。两种蛋白之间的主要结构差异，即DSP1富含谷氨酰胺的N端尾巴（HMGB1中不存在），并未干扰蛋白所研究的任何DNA结合特性。
