Schinzel R, Nidetzky B
Theodor-Boveri-Institut, Biozentrum, Universität Würzburg, Germany.
FEMS Microbiol Lett. 1999 Feb 15;171(2):73-9. doi: 10.1111/j.1574-6968.1999.tb13414.x.
Although glycogen and other alpha-1,4-D-glucan storage polysaccharides are present in many bacteria, only few glucan phosphorylases from bacteria have been identified and characterised on the protein or gene level. All bacterial phosphorylases follow the same catalytic mechanisms as their plant and vertebrate counterparts, but differ considerably in terms of their substrate specificity and regulation. The catalytic domains are highly conserved while the regulatory sites are only poorly conserved. The degree of conservation between bacterial and mammalian phosphorylases is comparable to that of other non-mammalian and mammalian alpha-glucan phosphorylases. Only for maltodextrin phosphorylase from E. coli the physiological role of the enzyme in the utilisation of maltodextrins is known in detail; that of all other phosphorylases remains still unclear. Roles in regulation of endogenous glycogen metabolism in periods of starvation, and sporulation, stress response or quick adaptation to changing environments are imaginable.
尽管糖原和其他α-1,4-D-葡聚糖储存多糖存在于许多细菌中，但在蛋白质或基因水平上，仅鉴定和表征了少数细菌来源的葡聚糖磷酸化酶。所有细菌磷酸化酶都遵循与植物和脊椎动物对应物相同的催化机制，但在底物特异性和调节方面有很大差异。催化结构域高度保守，而调节位点仅低度保守。细菌和哺乳动物磷酸化酶之间的保守程度与其他非哺乳动物和哺乳动物α-葡聚糖磷酸化酶相当。仅对于来自大肠杆菌的麦芽糊精磷酸化酶，该酶在麦芽糊精利用中的生理作用已得到详细了解；所有其他磷酸化酶的作用仍不清楚。可以想象它们在饥饿、孢子形成、应激反应或快速适应变化环境期间对内源糖原代谢的调节作用。
