CHARACTERIZATION OF A FUNCTIONAL VANADIUM-DEPENDENT BROMOPEROXIDASE IN THE MARINE CYANOBACTERIUM SYNECHOCOCCUS SP. CC9311
CHARACTERIZATION OF A FUNCTIONAL VANADIUM-DEPENDENT BROMOPEROXIDASE IN THE MARINE CYANOBACTERIUM SYNECHOCOCCUS SP. CC9311
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DOI：
10.1111/j.1529-8817.2011.01007.x
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发表时间：
2011-08-01
影响因子：
2.9
通讯作者：
Brahamsha, Bianca
中科院分区：
文献类型：
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作者：
Johnson, Todd L.;Palenik, Brian;Brahamsha, Bianca
钒依赖性溴过氧化物酶（VBPOs）的特点是能够使用过氧化氢氧化卤化物。这些酶在真核大型藻类中得到了很好的研究，已知它们能产生多种溴化次生代谢物。虽然基因在多个原核生物基因组中被标注为VBPO，但它们仍未被表征。沿海海洋蓝藻聚球菌（Synechococcus sp. CC9311）的基因组编码一个预测的VBPO (YP_731869.1, sync_2681)，在本研究中，我们发现从聚球菌无菌培养物中提取的蛋白质具有溴过氧化物酶活性，氧化溴化物和碘化物，但不氧化氯化物。用PAGE对聚球菌蛋白进行凝胶活性分析，发现有一条单带具有VBPO活性。通过液相色谱/质谱/质谱（LC/MS/MS）测序，该条带的肽与开放阅读框（ORF） sync_2681预测的VBPO序列一致。我们发现一个VBPO基因存在于一个密切相关的菌株，聚血球菌sp. WH8020中，但不存在于其他I枝聚血球菌菌株中，这与最近基因水平转移到聚血球菌中一致。多种蓝藻样VBPO基因在加利福尼亚海岸外的远洋环境中使用PCR检测到。对单细胞蓝藻中功能性VBPOs的研究可能有助于发现新的卤化分子，并有助于更好地了解这些生物的化学生态学和生理学。
Vanadium-dependent bromoperoxidases (VBPOs) are characterized by the ability to oxidize halides using hydrogen peroxide. These enzymes are well-studied in eukaryotic macroalgae and are known to produce a variety of brominated secondary metabolites. Though genes have been annotated as VBPO in multiple prokaryotic genomes, they remain un-characterized. The genome of the coastal marine cyanobacterium Synechococcus sp. CC9311 encodes a predicted VBPO (YP_731869.1, sync_2681), and in this study, we show that protein extracts from axenic cultures of Synechococcus possess bromoperoxidase activity, oxidizing bromide and iodide, but not chloride. In-gel activity assays of Synechococcus proteins separated using PAGE reveal a single band having VBPO activity. When sequenced via liquid chromatography/mass spectrometry/mass spectrometry (LC/MS/MS), peptides from the band aligned to the VBPO sequence predicted by the open reading frame (ORF) sync_2681. We show that a VBPO gene is present in a closely related strain, Synechococcus sp. WH8020, but not other clade I Synechococcus strains, consistent with recent horizontal transfer of the gene into Synechococcus. Diverse cyanobacterial-like VBPO genes were detected in a pelagic environment off the California coast using PCR. Investigation of functional VBPOs in unicellular cyanobacteria may lead to discovery of novel halogenated molecules and a better understanding of these organisms' chemical ecology and physiology.