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Globin-like蛋白质折叠类型识别 被引量:8
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作者 任文科 徐海松 李晓琴 《生物化学与生物物理进展》 SCIE CAS CSCD 北大核心 2008年第5期548-554,共7页
蛋白质折叠类型识别是蛋白质结构研究的重要内容.以SCOP中的Globin-like折叠为研究对象,选择其中序列同一性小于25%的17个代表性蛋白质为训练集,采用机器和人工结合的办法进行结构比对,产生序列排比,经过训练得到了适合Globin-like折叠... 蛋白质折叠类型识别是蛋白质结构研究的重要内容.以SCOP中的Globin-like折叠为研究对象,选择其中序列同一性小于25%的17个代表性蛋白质为训练集,采用机器和人工结合的办法进行结构比对,产生序列排比,经过训练得到了适合Globin-like折叠的概形隐马尔科夫模型(profile HMM)用于该折叠类型的识别.以Astral1.65中的68057个结构域样本进行检验,识别敏感度为99.64%,特异性100%.在折叠类型水平上,与Pfam和SUPERFAMILY单纯使用序列比对构建的HMM相比,所用模型由多于100个归为一个,仍然保持了很高的识别效果.结果表明:对序列相似度很低但具有相同折叠类型的蛋白质,可以通过引入结构比对的方法建立统一的HMM模型,实现高准确率的折叠类型识别. 展开更多
关键词 蛋白质 折叠类型识别 globin-like 隐马尔科夫模型 结构比对
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Genome mining of fungal globin-like enzymes for catalyzing the synthesis of linear terpenes
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作者 LIU Li CHEN Xiwei ZOU Yi 《Chinese Journal of Natural Medicines》 SCIE CAS CSCD 2022年第10期795-800,共6页
Genome mining for the search and discovery of two new globin-like enzymes,TriB from Fusarium poae and TutaA from Schizophyllum commne,are involved in the synthesis of two linear terpenes tricinonoic acid(1)and 2-buten... Genome mining for the search and discovery of two new globin-like enzymes,TriB from Fusarium poae and TutaA from Schizophyllum commne,are involved in the synthesis of two linear terpenes tricinonoic acid(1)and 2-butenedioic acid(3).Both in vivo heterologous biosynthesis and in vitro biochemical assays showed that these two enzymes catalyzed the C-C double bond cleavage of a cyclic sesquiterpene precursor(-)-germacrene D(7)and a linear diterpene backbone schizostain(2),respectively.Our work presents an unusual formation mechanism of linear terpenes from fungi and expands the functional skills of globin-like enzymes in the synthesis of terpene compounds. 展开更多
关键词 Genome mining globin-like enzyme Linear terpene C-C double bond cleavage FUNGI
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A Novel Multi-Stage Bispectral Deep Learning Method for Protein Family Classification
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作者 Amjed Al Fahoum Ala’a Zyout +1 位作者 Hiam Alquran Isam Abu-Qasmieh 《Computers, Materials & Continua》 SCIE EI 2023年第7期1173-1193,共21页
Complex proteins are needed for many biological activities.Folding amino acid chains reveals their properties and functions.They support healthy tissue structure,physiology,and homeostasis.Precision medicine and treat... Complex proteins are needed for many biological activities.Folding amino acid chains reveals their properties and functions.They support healthy tissue structure,physiology,and homeostasis.Precision medicine and treatments require quantitative protein identification and function.Despite technical advances and protein sequence data exploration,bioinformatics’“basic structure”problem—the automatic deduction of a protein’s properties from its amino acid sequence—remains unsolved.Protein function inference from amino acid sequences is the main biological data challenge.This study analyzes whether raw sequencing can characterize biological facts.A massive corpus of protein sequences and the Globin-like superfamily’s related protein families generate a solid vector representation.A coding technique for each sequence in each family was devised using two representations to identify each amino acid precisely.A bispectral analysis converts encoded protein numerical sequences into images for better protein sequence and family discrimination.Training and validation employed 70%of the dataset,while 30%was used for testing.This paper examined the performance of multistage deep learning models for differentiating between sixteen protein families after encoding and representing each encoded sequence by a higher spectral representation image(Bispectrum).Cascading minimized false positive and negative cases in all phases.The initial stage focused on two classes(six groups and ten groups).The subsequent stages focused on the few classes almost accurately separated in the first stage and decreased the overlapping cases between families that appeared in single-stage deep learning classification.The single-stage technique had 64.2%+/-22.8%accuracy,63.3%+/-17.1%precision,and a 63.2%+/19.4%F1-score.The two-stage technique yielded 92.2%+/-4.9%accuracy,92.7%+/-7.0%precision,and a 92.3%+/-5.0%F1-score.This work provides balanced,reliable,and precise forecasts for all families in all measures.It ensured that the new model was resilient to family variances and provided high-scoring results. 展开更多
关键词 globin-like superfamily numerical encoding bispectral analysis classification model deep convolutional neural network
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An Innovative Bispectral Deep Learning Method for Protein Family Classification
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作者 Isam Abu-Qasmieh Amjed Al Fahoum +1 位作者 Hiam Alquran Ala’a Zyout 《Computers, Materials & Continua》 SCIE EI 2023年第5期3971-3991,共21页
Proteins are essential for many biological functions.For example,folding amino acid chains reveals their functionalities by maintaining tissue structure,physiology,and homeostasis.Note that quantifiable protein charac... Proteins are essential for many biological functions.For example,folding amino acid chains reveals their functionalities by maintaining tissue structure,physiology,and homeostasis.Note that quantifiable protein characteristics are vital for improving therapies and precision medicine.The automatic inference of a protein’s properties from its amino acid sequence is called“basic structure”.Nevertheless,it remains a critical unsolved challenge in bioinformatics,although with recent technological advances and the investigation of protein sequence data.Inferring protein function from amino acid sequences is crucial in biology.This study considers using raw sequencing to explain biological facts using a large corpus of protein sequences and the Globin-like superfamily to generate a vector representation.The power of two representations was used to identify each amino acid,and a coding technique was established for each sequence family.Subsequently,the encoded protein numerical sequences are transformed into an image using bispectral analysis to identify essential characteristics for discriminating between protein sequences and their families.A deep Convolutional Neural Network(CNN)classifies the resulting images and developed non-normalized and normalized encoding techniques.Initially,the dataset was split 70/30 for training and testing.Correspondingly,the dataset was utilized for 70%training,15%validation,and 15%testing.The suggested methods are evaluated using accuracy,precision,and recall.The non-normalized method had 70%accuracy,72%precision,and 71%recall.68%accuracy,67%precision,and 67%recall after validation.Meanwhile,the normalized approach without validation had 92.4%accuracy,94.3%precision,and 91.1%recall.Validation showed 90%accuracy,91.2%precision,and 89.7%recall.Note that both algorithms outperform the rest.The paper presents that bispectrum-based nonlinear analysis using deep learning models outperforms standard machine learning methods and other deep learning methods based on convolutional architecture.They offered the best inference performance as the proposed approach improves categorization and prediction.Several instances show successful multi-class prediction in molecular biology’s massive data. 展开更多
关键词 globin-like superfamily numerical encoding bispectral analysis classification model deep convolutional neural network(CNN)
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KLFs对珠蛋白基因表达和红系分化的调控作用 被引量:8
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作者 熊倩 张昭军 方向东 《中国生物化学与分子生物学报》 CAS CSCD 北大核心 2011年第8期693-699,共7页
Krüppel样因子(Krüppel-like factors,KLFs)是一组与真核基因转录调控密切相关的锌指蛋白.KLFs高度保守的羧基末端含3个串联的Cys2His2型锌指结构,用于结合GC盒和CACCC盒等DNA序列.红细胞中特异表达的珠蛋白基因和许多红系调... Krüppel样因子(Krüppel-like factors,KLFs)是一组与真核基因转录调控密切相关的锌指蛋白.KLFs高度保守的羧基末端含3个串联的Cys2His2型锌指结构,用于结合GC盒和CACCC盒等DNA序列.红细胞中特异表达的珠蛋白基因和许多红系调控因子中都含有CACCC盒.已有研究发现,多个KLFs通过结合CACCC盒参与调控珠蛋白基因表达和红系分化,例如,KLF1通过结合β-珠蛋白启动子和位点控制区(locus control region,LCR),促进β-珠蛋白的表达、γ-向β-珠蛋白基因的转换和红系分化;KLF2、KLF11和KLF13分别促进ε-和γ-珠蛋白基因的表达;KLF4促进α-和γ-珠蛋白基因的表达;KLF3和KLF8则抑制ε-和γ-珠蛋白基因的表达.本文综述了KLFs调控珠蛋白基因表达和红系分化的研究进展. 展开更多
关键词 Krüppel样因子(KLFs) CACCC盒 珠蛋白 红系分化
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在Yunnanese(Aγδβ)^0—地贫3′缺失端点下游鉴别到两个增强子样顺序 被引量:1
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作者 黄小东 张俊武 《生物化学与生物物理进展》 SCIE CAS CSCD 北大核心 2002年第1期114-119,共6页
利用荧光酶报告基因系统搜索了Yunnanese (Aγδβ) 0 地中海贫血缺失 3′端点下游 11 5kb区域内的调控顺序 .确定缺失 3′端点立即下游区 1 7kb片段 ,在人红白血病细胞K5 6 2及鼠红白血病细胞MELGM979中 ,可使γ 珠蛋白基因启动子驱... 利用荧光酶报告基因系统搜索了Yunnanese (Aγδβ) 0 地中海贫血缺失 3′端点下游 11 5kb区域内的调控顺序 .确定缺失 3′端点立即下游区 1 7kb片段 ,在人红白血病细胞K5 6 2及鼠红白血病细胞MELGM979中 ,可使γ 珠蛋白基因启动子驱动的荧光酶基因表达增加 3 8~ 4 0倍 ,而在HeLa细胞中仅增加 1 5倍 .位于缺失 3′端点约 10kb的一个长 1 4kb片段在K5 6 2和MELGM979中 ,可使γ 基因启动子驱动的荧光酶基因表达增加 2 4~2 9倍 ,而在HeLa细胞中无增加 .结果说明这两段顺序均有增强子活性 ,并且这种活性具有一定的红细胞特异性 .进一步证明 1 7kb片段内包含多个转录调节蛋白结合模体的 430bp片段包含了 1 7kb片段的大部分增强子活性 .这些结果为缺失导致增强子样顺序并入到接近Gγ 基因 ,是Yunnanese (Aγδβ) 0 地贫缺失突变体中胎儿Gγ 珠蛋白基因 ,在成人期持续活跃表达原因的假设提供了实验证据 . 展开更多
关键词 Gγ-珠蛋白基因 γ(Aδβ)^0-地中海贫血 增强子样顺序 成人 胎儿
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人β族珠蛋白基因调控域中结合蛋白的研究
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作者 陈琳 郭丹 华子春 《海军医高专学报》 1995年第1期12-13,24,共3页
本文以小鼠骨髓细胞为材料,测定了人血红蛋白ε.基因5′端上游序列超敏感点Ⅱ(HSⅡ)中340bp,380bp两段DNA的结合白蛋.通过凝胶阻滞实验发现.340bpDNA有一较强的结合蛋白,而380dbpDNA有较弱的结合蛋白.
关键词 珠蛋白 β族珠蛋白基因 基因调控 结合蛋白
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Kruppel样因子1在珠蛋白基因表达调控中的作用
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作者 李静 赖永榕 《国际输血及血液学杂志》 CAS 2015年第4期355-357,共3页
Krtippel样因子(KLF)1属于锌指蛋白家族,是红细胞系特异性转录因子。KLF1在红细胞生成中发挥多种作用,如可通过调节染色质构象,活化β珠蛋白基因转录;可根据不同作用背景、协同因子及KLFl蛋白修饰状态,对γ珠蛋白基因表达起着活... Krtippel样因子(KLF)1属于锌指蛋白家族,是红细胞系特异性转录因子。KLF1在红细胞生成中发挥多种作用,如可通过调节染色质构象,活化β珠蛋白基因转录;可根据不同作用背景、协同因子及KLFl蛋白修饰状态,对γ珠蛋白基因表达起着活化或抑制的调控作用。目前,KLF1对珠蛋白基因表达的确切调控机制迄今仍未阐明,尚需进一步研究探讨。笔者拟就KLF1在珠蛋白基因表达调控中的作用进行综述,旨在初步探讨KLF1作为β地中海贫血基因治疗靶向因子的可能性。 展开更多
关键词 Kruppel样因子 Β珠蛋白 Γ珠蛋白
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Interactions between HMG proteins and the core sequence of DNaseI hypersensitive site 2 in the locus control region (LCR) of the human β-Mike globin gene cluster
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作者 赵晖 张树冰 +1 位作者 蒋俶 钱若兰 《Science China(Life Sciences)》 SCIE CAS 2000年第6期631-636,共6页
HMG proteins are abundant chromosomal non-histone proteins. It has been suggested that the HMG proteins may play an important role in the structure and function of chromatin. In the present study, the binding of HMG p... HMG proteins are abundant chromosomal non-histone proteins. It has been suggested that the HMG proteins may play an important role in the structure and function of chromatin. In the present study, the binding of HMG proteins (HMG1/2 and HMG14/17) to the core DNA sequence of DNasel hypersensitive site 2 (HS2core DNA sequence, -10681-10970 bp) in the locus control region (LCR) of the human β-like globin gene cluster has been examined by using both the in vitro nucleosome reconstitution and the gel mobility shift assays. Here we show that HMG1/2 can bind to the naked HS2core DNA sequence, however, HMG 14/17 cannot. Using the in vitro nucleosome reconstitution we demonstrate that HMG14/17 can bind to the HS2core DNA sequence which is assembled into nucleosomes with the core histone octamer transferred from chicken erythrocytes. In contrast, HMG 1/2 cannot bind to the nucleosomes reconstituted in vitro with the HS2core DNA sequence. These results indicate that the binding patterns between HMG proteins and 展开更多
关键词 HMG proteins HUMAN β-like GLOBIN gene CLUSTER DNASEI HYPERSENSITIVE SITE 2 (HS2) the in vitro nucleosome reconstitution.
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