Utilization of polyisoprene (natural rubber) as a carbon source by Steroidobacter cummioxidans 35Y (previously Xanthomonas sp. strain 35Y) depends on the formation and secretion of rubber oxygenase A (RoxA). RoxA is a dioxygenase that cleaves polyisoprene to 12-oxo-4,8-dimethyl-trideca-4,8-diene-1-al (ODTD), a suitable growth substrate for S. cummioxidans. RoxA harbours two non-equivalent, spectroscopically distinguishable haem centres. A dioxygen molecule is bound to the N-terminal haem of RoxA and identifies this haem as the active site. In this study, we provide insights into the nature of this unusually stable dioxygen-haem coordination of RoxA by a re-evaluation of previously published together with newly obtained biophysical data on the cleavage of polyisoprene by RoxA. In combination with the meanwhile available structure of RoxA we are now able to explain several uncommon and previously not fully understood features of RoxA, the prototype of rubber oxygenases in Gram-negative rubber-degrading bacteria.

中文翻译：

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旨在了解二血红素双加氧酶 RoxA 对聚异戊二烯的酶裂解。

氧化类固醇杆菌35Y（以前称为黄单胞菌菌株 35Y）利用聚异戊二烯（天然橡胶）作为碳源取决于橡胶加氧酶 A (RoxA) 的形成和分泌。RoxA 是一种双加氧酶，可将聚异戊二烯裂解为 12- oxo -4,8- ​​d imethyl - trideca-4,8- ​​d iene-1-al (ODTD)，这是氧化链球菌的合适生长底物。RoxA 拥有两个不等价、光谱上可区分的血红素中心。双氧分子与 RoxA 的 N 端血红素结合，并将该血红素识别为活性位点。在这项研究中，我们通过重新评估先前发表的以及新获得的有关 RoxA 裂解聚异戊二烯的生物物理数据，深入了解 RoxA 这种异常稳定的双氧-血红素协调的性质。结合当前可用的 RoxA 结构，我们现在能够解释 RoxA 的几个不常见且以前未完全理解的特征，RoxA 是革兰氏阴性橡胶降解细菌中橡胶加氧酶的原型。