Machabée S, Wall L, Morse D
Institut de Recherche en Biologie Végétale, Université de Montréal, Canada.
Plant Mol Biol. 1994 Apr;25(1):23-31. doi: 10.1007/BF00024195.
The luciferin-binding protein (LBP) of the dinoflagellate Gonyaulax polyedra is encoded by a large gene family with at least two different members. To more fully understand the expression and genomic organization of this gene family, 40 full-length LBP cDNAs were isolated and mapped with the restriction enzymes Xho I, Eco RI, Pvu II and Hind III. All cDNAs isolated could be placed into one of two groups called LBP alpha and LBP beta. Two LBP alpha group cDNAs were completely sequenced and were found to share 99% identity at both the nucleotide and protein levels. One LBP beta cDNA was sequenced and was found to share only 86% sequence identity with the LBP alpha group at both the nucleotide and protein levels. Both groups of message appear to be expressed at nearly equal levels since (1) two-dimensional gels of purified LBP show two protein isoforms present in roughly equal amounts and (2) northern blots using group-specific probes suggest that cellular levels of LBP alpha and LBP beta mRNAs are identical. Genomic Southern blots using group-specific probes suggests that the copy number of both gene groups is very similar and that LBP gene loci are organized as tandem repeats of either LBP alpha or LBP beta sequences.
多甲藻（Gonyaulax polyedra）的虫荧光素结合蛋白（LBP）由一个大型基因家族编码，该家族至少有两个不同成员。为了更全面地了解这个基因家族的表达和基因组组织，分离出40个全长LBP cDNA，并使用限制性内切酶Xho I、Eco RI、Pvu II和Hind III进行定位。所有分离出的cDNA都可归入两个组之一，即LBPα和LBPβ。对两个LBPα组的cDNA进行了全序列测定，发现它们在核苷酸和蛋白质水平上的同一性均为99%。对一个LBPβ cDNA进行了测序，发现它在核苷酸和蛋白质水平上与LBPα组的序列同一性仅为86%。两组信息似乎以几乎相等的水平表达，因为（1）纯化的LBP的二维凝胶显示两种蛋白质异构体的含量大致相等，（2）使用组特异性探针的Northern印迹表明LBPα和LBPβ mRNA的细胞水平相同。使用组特异性探针的基因组Southern印迹表明，两个基因组的拷贝数非常相似，并且LBP基因位点以LBPα或LBPβ序列的串联重复形式组织。
