title: The functional divergence of two glgP homologues in Synechocystis sp. PCC 6803.
abstract: Glycogen phosphorylase (GlgP, EC 2.4.1.1) catalyzes the cleavage of glycogen into glucose-1-phosphate (Glc-1-P), the first step in glycogen catabolism. Two glgP homologues are found in the genome of Synechocystis sp. PCC 6803, a unicellular cyanobacterium: sll1356 and slr1367. We report on the different functions of these glgP homologues. sll1356, rather than slr1367, is essential for growth at high temperatures. On the other hand, when CO2-fixation and the supply of glucose are both limited, slr1367 is the key factor in glycogen metabolism. In cells growing autotrophically, sll1356 plays a more important role in glycogen digestion than slr1367. This functional divergence is also supported by a phylogenetic analysis of glgP homologues in cyanobacteria.
authors.affiliation: The State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, Hubei, China.
authors.forename: Juan
authors.initials: J
authors.lastname: Fu
authors.forename: Xudong
authors.initials: X
authors.lastname: Xu
mesh_terms: D019295:Computational Biology; D015964:Gene Expression Regulation, Bacterial; D005798:Genes, Bacterial; D006003:Glycogen / Q000378:metabolism; D024981:Glycogen Phosphorylase / Q000235:genetics* / Q000378:metabolism*; D006358:Hot Temperature; D009154:Mutation; D010788:Photosynthesis; D010802:Phylogeny; D016415:Sequence Alignment; D017385:Sequence Homology; D046939:Synechocystis / Q000201:enzymology* / Q000235:genetics / Q000254:growth & development
chemical_list: D006003:Glycogen; D024981:Glycogen Phosphorylase