The Synechocystis sp. PCC 6803 Genome Encodes Up to Four 2-Phosphoglycolate Phosphatases
The Synechocystis sp. PCC 6803 Genome Encodes Up to Four 2-Phosphoglycolate Phosphatases
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集胞藻属 sp.
DOI：
10.3389/fpls.2018.01718
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发表时间：
2018
影响因子：
5.6
通讯作者：
M. Hagemann
中科院分区：
文献类型：
--
作者：
S. Rai;Stefan Lucius;R. Kern;H. Bauwe;A. Kaplan;J. Kopka;M. Hagemann
光呼吸磷酸乙醇酸（2 PG）代谢是蓝藻，藻类和植物所必需的。该途径的第一种酶，2 PG磷酸酶（PGPase），已知来自植物和藻类，但在蓝藻中几乎没有研究。计算机模拟分析显示，模式蓝藻集胞藻PCC 6803基因组中有4个候选基因（slr 0458、slr 0586、sll 1349和slr 1762），均属于2-卤酸脱卤酶（HAD）超家族，可能编码PGP酶蛋白。然而，在已知的藻类和植物的PGPases相反，推定的蓝藻PGPases属于另一个HAD亚家族，这意味着在真核光养生物的PGPases不起源于蓝藻PGPases。为了验证它们的功能，这四个基因被单独和组合灭活。仅在Δ sll 1349中观察到光呼吸突变体典型的轻度高CO2需求（HCR）生长表型。组合失活增强了特异性双突变体和三突变体的HCR表型。在E. coli中表达的蛋白质具有较高的PGPase活性，但只有纯化的Slr 0458蛋白具有PGPase活性。因此，我们建议，一个财团多达四个光呼吸PGPases可能会启动光呼吸2 PG代谢集胞藻。我们认为，这种必需的酶活性的冗余可能与蓝藻的高度适应性的生活方式，如集胞藻属PCC 6803，这使他们能够在非常不同的条件下生长。
Photorespiratory phosphoglycolate (2PG) metabolism is essential for cyanobacteria, algae, and plants. The first enzyme of the pathway, 2PG phosphatase (PGPase), is known from plants and algae but was scarcely investigated in cyanobacteria. In silico analysis revealed four candidate genes (slr0458, slr0586, sll1349, and slr1762) in the genome of the model cyanobacterium Synechocystis sp. PCC 6803 that all belong to the 2-haloacid dehalogenase (HAD) superfamily and could possibly encode PGPase proteins. However, in contrast to known algal and plant PGPases, the putative cyanobacterial PGPases belong to another HAD subfamily implying that PGPases in eukaryotic phototrophs did not originate from cyanobacterial PGPases. To verify their function, these four genes were inactivated both individually and in combination. A mild high-CO2-requiring (HCR) growth phenotype typical for photorespiratory mutants was observed only in Δsll1349. Combinatorial inactivation enhanced the HCR phenotype in specific double and triple mutants. Heterologous expression of the putative cyanobacterial PGPases in E. coli led to higher PGPase activities in crude cell extracts, but only the purified Slr0458 protein showed PGPase activity. Hence, we propose that a consortium of up to four photorespiratory PGPases may initiate photorespiratory 2PG metabolism in Synechocystis. We suggest that redundancy of this essential enzyme activity could be related to the highly adaptive lifestyle of cyanobacteria such as Synechocystis sp. PCC 6803, which allows them to grow under very diverse conditions.
影响因子：
5.1
作者：
Meissner, Sven;Steinhauser, Dirk;Dittmann, Elke
通讯作者：
Dittmann, Elke
影响因子：
5.1
作者：
Haimovich-Dayan, Maya;Lieman-Hurwitz, Judy;Kaplan, Aaron
通讯作者：
Kaplan, Aaron
影响因子：
7
作者：
Do, CB;Mahabhashyam, MSP;Batzoglou, S
通讯作者：
Batzoglou, S