Crystal Structures of Human Muscle Fructose-1, 6-Bisphosphatase: Novel Quaternary States, Enhanced AMP Affinity, and Allosteric Signal Transmission Pathway

	Crystal Structures of Human Muscle Fructose-1, 6-Bisphosphatase: Novel Quaternary States, Enhanced AMP Affinity, and Allosteric Signal Transmission Pathway
	Shi, R; Chen, ZY; Zhu, DW; Li, CM; Shan, YF; Xu, GJ; Lin, SX
刊名	PLOS ONE
	2013
卷号	8 期号:9 页码:e71242-e71242
通讯作者	Lin, SX (reprint author), Univ Laval, Lab Mol Endocrinol & Oncol, Ctr Hosp Univ Quebec Res Ctr CHUQ CHUL, Dept Mol Med, Quebec City, PQ, Canada.,sheng-xiang.lin@crchul.ulaval.ca
英文摘要	Fructose-1,6-bisphosphatase, a key enzyme in gluconeogenesis, is subject to metabolic regulation. The human muscle isozyme is significantly more sensitive towards the allosteric inhibitor, AMP, than the liver isoform. Here we report crystal structures and kinetic studies for wild-type human muscle Fru-1,6-Pase, the AMP-bound (1.6 angstrom), and product-bound complexes of the Q32R mutant, which was firstly introduced by an error in the cloning. Our high-resolution structure reveals for the first time that the higher sensitivity of the muscle isozyme towards AMP originates from an additional water-mediated, H-bonded network established between AMP and the binding pocket. Also present in our structures are a metaphosphate molecule, alternate conformations of Glu97 coordinating Mg2+, and possible metal migration during catalysis. Although the individual subunit is similar to previously reported Fru-1,6-Pase structures, the tetrameric assembly of all these structures deviates from the canonical R-or T-states, representing novel tetrameric assemblies. Intriguingly, the concentration of AMP required for 50% inhibition of the Q32R mutant is increased 19-fold, and the cooperativity of both AMP and Mg2+ is abolished or decreased. These structures demonstrate the Q32R mutation affects the conformations of both N-terminal residues and the dynamic loop 52-72. Also importantly, structural comparison indicates that this mutation in helix alpha 2 is detrimental to the R-to-T conversion as evidenced by the absence of quaternary structural changes upon AMP binding, providing direct evidence for the critical role of helix alpha 2 in the allosteric signal transduction.
学科主题	Science & Technology - Other Topics
类目[WOS]	Multidisciplinary Sciences
关键词[WOS]	SITE-DIRECTED MUTAGENESIS ; PORCINE FRUCTOSE-1,6-BISPHOSPHATASE ; ESCHERICHIA-COLI ; R-STATE ; RECOMBINANT PORCINE ; INHIBITION ; ACTIVATION ; 1,6-BISPHOSPHATASE ; DIPHOSPHATASE ; RESOLUTION
收录类别	SCI
语种	英语
WOS记录号	WOS:000325223900005
内容类型	期刊论文
版本	出版稿
源URL	[http://202.127.25.143/handle/331003/423]
专题	上海生化细胞研究所_上海生科院生化细胞研究所
推荐引用方式 GB/T 7714	Shi, R,Chen, ZY,Zhu, DW,et al. Crystal Structures of Human Muscle Fructose-1, 6-Bisphosphatase: Novel Quaternary States, Enhanced AMP Affinity, and Allosteric Signal Transmission Pathway[J]. PLOS ONE,2013,8(9):e71242-e71242.
APA	Shi, R.,Chen, ZY.,Zhu, DW.,Li, CM.,Shan, YF.,...&Lin, SX.(2013).Crystal Structures of Human Muscle Fructose-1, 6-Bisphosphatase: Novel Quaternary States, Enhanced AMP Affinity, and Allosteric Signal Transmission Pathway.PLOS ONE,8(9),e71242-e71242.
MLA	Shi, R,et al."Crystal Structures of Human Muscle Fructose-1, 6-Bisphosphatase: Novel Quaternary States, Enhanced AMP Affinity, and Allosteric Signal Transmission Pathway".PLOS ONE 8.9(2013):e71242-e71242.