CAJ | 학술논문

蓝藻抗病毒蛋白-N(Cyanovirin-N,CV-N)具有广谱抗病毒活性,其同源物构成CVNH(cyanovirin-N ho-mology)蛋白家族,并且家族成员的抗人类免疫缺陷病毒结构域在进化上非常保守.文章通过重建基因树对CVNH结构域的"零散分布"特点作了更为细致的了解,发现在黑曲霉、费氏曲菌、产黄青霉、粗糙脉孢霉、蓝杆藻和水蕨等物种中存在多份该结构域拷贝.在此基础上,分别采用机理式模型(Mechanistic model)和MEC模型(Mechanistic-empirical combination model)对CVNH结构域序列位点进行适应性进化分析,结果显示:1)两类模型均未检测到统计上显著的正选择位点;2)净化选择对CVNH起主导作用;3)MEC模型更适合所研究的数据.进一步使用"支-特异"模型和"支-位点"模型对蓝杆菌菌株7822和7424的祖先分支进行检测,发现该分支经历过适应性进化,并且鉴定出6个正选择位点(34L、63L、13H、76C,78K和80I).
람조항병독단백-N(Cyanovirin-N,CV-N)구유엄보항병독활성,기동원물구성CVNH(cyanovirin-N ho-mology)단백가족,병차가족성원적항인류면역결함병독결구역재진화상비상보수.문장통과중건기인수대CVNH결구역적"령산분포"특점작료경위세치적료해,발현재흑곡매、비씨곡균、산황청매、조조맥포매、람간조화수궐등물충중존재다빈해결구역고패.재차기출상,분별채용궤리식모형(Mechanistic model)화MEC모형(Mechanistic-empirical combination model)대CVNH결구역서렬위점진행괄응성진화분석,결과현시:1)량류모형균미검측도통계상현저적정선택위점;2)정화선택대CVNH기주도작용;3)MEC모형경괄합소연구적수거.진일보사용"지-특이"모형화"지-위점"모형대람간균균주7822화7424적조선분지진행검측,발현해분지경력과괄응성진화,병차감정출6개정선택위점(34L、63L、13H、76C,78K화80I).
Cyanovirin-N (CV-N) is a novel protein with broad-spectrum antiviral activity. Its homologs constitute a pro-tein family known as CVNH (Cyanovirin-N homology), which possess the evolutionarily conserved anti-HIV (Human im-munodeficiency virus) domain. In this study, more details about the patchy organism distribution of CVNH domain were explored by reconstructing gene trees. Duplicated CVNH sequences were also identified in a wide range of species includ-ing Aspergillus niger, Neosartorya fischeri NRRL 181, Penicillium chrysogenum Wisconsin 54-1255, Neurospora crassa, Cyanothece sp. PCC, and Ceratopteris richardii. Besides these findings, both the mechanistic and mechanistic-empirical combination (MEC) models were used to analyze the adaptive evolution of amino acid sites in the CVNH domain. Our results showed that: (1) neither model reveals significant sites undergoing positive selection; (2) purifying selection has played a dominant role during CVNH evolution; and (3) the MEC model better fits the CVNH data set. Furthermore, the ancestral branch leading to Cyanothece sp. PCC 7822 and 7424 were examined using "branch-specific" and "branch-site" models. Six positively selected sites (34L, 63L, 13H, 76C, 78K, and 80I) were identified on the branch.