CAJ | 학술논문

多不饱和脂肪酸是生物膜的重要组成成分，在维持细胞膜的流动性与低温适应性中起到重要作用。以低温微生物嗜冷黄杆菌为对象，主要采用多重序列比对、同源建模、模型评价等生物信息学技术与方法，分析与研究了多不饱和脂肪酸代谢重要相关蛋白酰基-Acp去饱和酶的序列组成与基序特征、系统进化与重要活性位点中心，模建并高评分地获得了其三维空间结构。系统发育分析表明，嗜冷黄杆菌等低温耐受菌与植物类物种的酰基-Acp去饱和酶的分子进化关系较近，而与其他细菌的分子进化关系较远。多序列基序分析显示，多数物种含有HxxxxH、HxxHH和HxxHH等3个组氨酸保守区，为二Fe离子结合区。 Swiss-model对嗜冷黄杆菌的酰基-Acp去饱和酶进行的同源建模及其模型分析发现，其也具备与Fe 离子相互作用的活性区，与 Fe离子直接作用的活性位点有His114、Glu111、Glu76、His200、Glu19和Glu164，嗜冷黄杆菌的酰基-Acp去饱和酶有异于其它细菌的特异性。这从某种程度上揭示，相对于常温菌而言，低温耐受菌可能存在着低温相关蛋白酶的序列乃至功效上的差异。对于深入了解细菌耐低温机制，低温相关蛋白差异性分析及改造与应用均有重要的意义与价值。
다불포화지방산시생물막적중요조성성분，재유지세포막적류동성여저온괄응성중기도중요작용。이저온미생물기랭황간균위대상，주요채용다중서렬비대、동원건모、모형평개등생물신식학기술여방법，분석여연구료다불포화지방산대사중요상관단백선기-Acp거포화매적서렬조성여기서특정、계통진화여중요활성위점중심，모건병고평분지획득료기삼유공간결구。계통발육분석표명，기랭황간균등저온내수균여식물류물충적선기-Acp거포화매적분자진화관계교근，이여기타세균적분자진화관계교원。다서렬기서분석현시，다수물충함유HxxxxH、HxxHH화HxxHH등3개조안산보수구，위이Fe리자결합구。 Swiss-model대기랭황간균적선기-Acp거포화매진행적동원건모급기모형분석발현，기야구비여Fe 리자상호작용적활성구，여 Fe리자직접작용적활성위점유His114、Glu111、Glu76、His200、Glu19화Glu164，기랭황간균적선기-Acp거포화매유이우기타세균적특이성。저종모충정도상게시，상대우상온균이언，저온내수균가능존재착저온상관단백매적서렬내지공효상적차이。대우심입료해세균내저온궤제，저온상관단백차이성분석급개조여응용균유중요적의의여개치。
Polyunsaturated fatty acids are important components of biofilms , which plays an important role in maintaining of membrane fluidity.In this paper, multiple sequence alignment , homology modeling , model evaluation and other bioinformatics methods were used to analyze the sequence composition , motifs characteristic , system evolution and important center of the active sites , as well as model-ing and high score evaluation of the modelled three-dimensional structure of acyl-ACP desaturase in psychrophilic microorganism of Fla-vobacterium related to the metabolism of polyunsaturated fatty acids .Phylogenetic analysis showed that the molecular evolutionary rela-tionship between Flavobacterium and plant species was closer than other bacteria .Multiple sequence motif analysis showed that the ma-jority of species had three conserved histidine regions bonded to iron atoms .Homology modeling by Swiss-Model and model analysis of Flavobacterium acyl-ACP desaturase disclosed that it also had the active regions which could bond to iron atoms , and the active sites were composed of His114, Glu111, Glu76, His200, Glu19 and Glu164.The psychrophilic Flavobacterium acyl-ACP desaturase was quite different from other bacteria .Relative to normal temperature bacteria , the structure and function of low temperature resistant bac-teria might be different .