Adjé C A, Opperdoes F R, Michels P A
Research Unit for Tropical Diseases, Christian de Duve Institute of Cellular Pathology (ICP), Laboratory of Biochemistry, Catholic University of Louvain (UCL), Brussels, Belgium.
Gene. 1998 Sep 14;217(1-2):91-9. doi: 10.1016/s0378-1119(98)00356-4.
In the protozoan kinetoplastid organism Trypanoplasma borreli, phosphoglycerate kinase (PGK) activity was found in two different cell compartments: 80% in the cytosol and 20% in peroxisome-like organelles called glycosomes. However, only one functional pgk gene could be detected, in addition to a pseudo-pgk gene. No short-range linkage could be established between these two genes, although they are presumably present on the same chromosome. The intact gene codes for a polypeptide of 411 amino acids, with a C-terminal extension of four residues, -VAKF, a sequence with probably a low targeting efficiency for glycosomes. The calculated net charge and molecular mass of the encoded polypeptide are +13 and 44230Da, respectively. In other Kinetoplastida, different tandemly arranged genes code for distinct PGK isoenzymes in glycosomes and cytosol. By comparison of the pgk gene organization, and a phylogenetic analysis, we have traced a plausible scenario of the evolution of the PGK isoenzymes in these organisms and of the enzymes' intracellular compartmentation.
在原生动物动质体生物伯氏锥虫中，磷酸甘油酸激酶（PGK）活性存在于两个不同的细胞区室中：80%存在于细胞质中，20%存在于称为糖体的过氧化物酶体样细胞器中。然而，除了一个假pgk基因外，只能检测到一个功能性pgk基因。尽管这两个基因可能位于同一条染色体上，但它们之间无法建立短程连锁关系。完整基因编码一个由411个氨基酸组成的多肽，其C端有四个残基的延伸，即-VAKF，这一序列对糖体的靶向效率可能较低。编码多肽的计算净电荷和分子量分别为+13和44230Da。在其他动质体中，不同的串联排列基因编码糖体和细胞质中不同的PGK同工酶。通过比较pgk基因组织并进行系统发育分析，我们描绘了这些生物中PGK同工酶以及酶的细胞内区室化进化的合理情景。
