Chen Kuan-Ming, Martemyanova Natalia, Lu Yongjian, Shindo Keisuke, Matsuo Hiroshi, Harris Reuben S
University of Minnesota, Department of Biochemistry, Molecular Biology and Biophysics, Minneapolis, MN 55455, United States.
FEBS Lett. 2007 Oct 2;581(24):4761-6. doi: 10.1016/j.febslet.2007.08.076. Epub 2007 Sep 7.
APOBEC3G is a single-strand DNA cytosine deaminase capable of blocking retrovirus and retrotransposon replication. APOBEC3G has two conserved zinc-coordinating motifs but only one is required for catalysis. Here, deletion analyses revealed that the minimal catalytic domain consists of residues 198-384. Size exclusion assays indicated that this protein is monomeric. Many (31/69) alanine substitution derivatives of APOBEC3G198-384 retained significant to full levels of activity. These data corroborated an APOBEC2-based structural model for the catalytic domain of APOBEC3G indicating that most non-essential residues are solvent accessible and most essential residues cluster within the protein core.
载脂蛋白B mRNA编辑酶催化多肽样蛋白3G（APOBEC3G）是一种单链DNA胞嘧啶脱氨酶，能够阻断逆转录病毒和逆转座子的复制。APOBEC3G有两个保守的锌配位基序，但催化作用仅需其中一个。在此，缺失分析显示最小催化结构域由198 - 384位残基组成。尺寸排阻分析表明该蛋白为单体。APOBEC3G198 - 384的许多（31/69）丙氨酸替代衍生物保留了显著至完全水平的活性。这些数据证实了基于载脂蛋白B mRNA编辑酶催化多肽样蛋白2（APOBEC2）的APOBEC3G催化结构域结构模型，表明大多数非必需残基可接触溶剂，且大多数必需残基聚集在蛋白质核心内。
