Data_Sheet_1_A Hydrophobic Small Protein, BpOF4_01690, Is Critical for Alkaliphily of Alkaliphilic Bacillus pseudofirmus OF4.PDF

A monocistronic small protein, BpOF4_01690, was annotated in alkaliphilic Bacillus pseudofirmus OF4. It comprises 59 amino acids and is hydrophobic. Importantly, homologs of this protein were identified only in alkaliphiles. In this study, a mutant with a BpOF4_01690 gene deletion (designated Δ01690) exhibited weaker growth than that of the wild type in both malate-based defined and glucose-based defined media under low-sodium conditions at pH 10.5. Additionally, the enzymatic activity of the respiratory chain of Δ01690 was much lower than that of the wild type. These phenotypes were similar to those of a ctaD deletion mutant and an atpB-F deletion mutant. Therefore, we hypothesize that BpOF4_01690 plays a critical role in oxidative phosphorylation under highly alkaline conditions.

在嗜碱性芽孢杆菌假固菌OF4中，单顺反子小蛋白BpOF4_01690得以注释。该蛋白由59个氨基酸组成，性质为疏水性。值得注意的是，该蛋白的同源物仅见于嗜碱性微生物。在本研究中，具有BpOF4_01690基因缺失（命名为Δ01690）的突变体在低钠条件下，于pH 10.5的苹果酸和葡萄糖定义培养基中，其生长速度较野生型显著减弱。此外，Δ01690的呼吸链酶活性远低于野生型。这些表型与ctaD缺失突变体及atpB-F缺失突变体相似。因此，我们推测BpOF4_01690在高度碱性条件下在氧化磷酸化过程中发挥着至关重要的作用。