Serine 363 of a Hydrophobic Region of Archaeal Ribulose 1,5-Bisphosphate Carboxylase/Oxygenase from Archaeoglobus fulgidus and Thermococcus kodakaraensis Affects CO2/O2 Substrate Specificity and Oxygen Sensitivity.
Serine 363 of a Hydrophobic Region of Archaeal Ribulose 1,5-Bisphosphate Carboxylase/Oxygenase from Archaeoglobus fulgidus and Thermococcus kodakaraensis Affects CO2/O2 Substrate Specificity and Oxygen Sensitivity.
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DOI：
10.1371/journal.pone.0138351
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发表时间：
2015
期刊：
影响因子：
3.7
通讯作者：
Tabita FR
中科院分区：
文献类型：
--
作者：
Kreel NE;Tabita FR
酵母核酮糖1，5-二磷酸羧化酶/加氧酶（RubisCO）与其它RubisCO酶不同，并被分类为III型酶，与化能自养细菌以及原核和真核光养生物典型的I型和II型RubisCO相反。来自古生菌的III型酶特别有趣，因为这些蛋白质中的几种对分子氧表现出不寻常的和可逆的敏感性，包括来自闪烁古生菌的酶。以前的研究与A。荧光藻RbcL 2已经显示了Met-295在氧敏感性中的重要性，并指出了在所有RubisCO蛋白中保守的疏水口袋中发现的另一个残基（Ser-363）的潜在意义。本研究以A.闪电RbcL 2;疏水口袋的这个和其它残基的各种变化表明并明确确定了Ser-363在与氧相互作用方面的重要性。此外，以前的研究结果表明，对与A. fulgidus RbcL2.本文表明T. Kodakaraensis酶表现出与A.并且也是氧敏感的，具有参与氧相互作用的等同残基。
Archaeal ribulose 1, 5-bisphospate carboxylase/oxygenase (RubisCO) is differentiated from other RubisCO enzymes and is classified as a form III enzyme, as opposed to the form I and form II RubisCOs typical of chemoautotrophic bacteria and prokaryotic and eukaryotic phototrophs. The form III enzyme from archaea is particularly interesting as several of these proteins exhibit unusual and reversible sensitivity to molecular oxygen, including the enzyme from Archaeoglobus fulgidus. Previous studies with A. fulgidus RbcL2 had shown the importance of Met-295 in oxygen sensitivity and pointed towards the potential significance of another residue (Ser-363) found in a hydrophobic pocket that is conserved in all RubisCO proteins. In the current study, further structure/function studies have been performed focusing on Ser-363 of A. fulgidus RbcL2; various changes in this and other residues of the hydrophobic pocket point to and definitively establish the importance of Ser-363 with respect to interactions with oxygen. In addition, previous findings had indicated discrepant CO2/O2 specificity determinations of the Thermococcus kodakaraensis RubisCO, a close homolog of A. fulgidus RbcL2. It is shown here that the T. kodakaraensis enzyme exhibits a similar substrate specificity as the A. fulgidus enzyme and is also oxygen sensitive, with equivalent residues involved in oxygen interactions.