Identification and characterization of a novel GNAT superfamily N(α) -acetyltransferase from Salinicoccus halodurans H3B36.
Identification and characterization of a novel GNAT superfamily N(α) -acetyltransferase from Salinicoccus halodurans H3B36.
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盐球菌 H3B36 中新型 GNAT 超家族 Nα-乙酰转移酶的鉴定和表征
DOI：
10.1111/1751-7915.13998
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发表时间：
2022-05
影响因子：
5.7
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中科院分区：
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N-乙酰基-α-α-赖氨酸是盐藻H3B36菌株的有机细胞保护剂，是一种新型的相容溶质。从该中度嗜盐菌中分离到一个新的赖氨酸N-α-乙酰基转移酶基因(Shkat)，该基因编码一种仅在α位催化赖氨酸乙酰化的酶，并在大肠杆菌中表达。序列分析表明，ShKAT含有一个高度保守的焦磷酸结合环(Arg-Gly-Asn-Gly-Asn-Gly)，这是GNAT超家族的特征。ShKAT独家识别游离氨基酸为底物，包括赖氨酸和其他碱性氨基酸。该酶具有较宽的最适pH值范围，耐高碱高盐条件。作为GNAT超家族的新成员，ShKAT是第一个以游离赖氨酸为底物的酶。我们相信，这项工作扩大了对蚊子超家族的认识，并揭示了shkat基因在抵抗极端条件的基因工程中的巨大潜力。从盐藻H3B36中鉴定出一个新的赖氨酸N-α-乙酰基转移酶基因(Shkat)，该基因编码一种仅在α位催化赖氨酸乙酰化的酶，并在大肠杆菌中表达。序列分析表明，ShKAT含有一个高度保守的焦磷酸结合环(Arg-Gly-Asn-Gly-Asn-Gly)，这是GNAT超家族的特征。ShKAT是唯一识别游离氨基酸为底物的酶，是GNAT超家族中第一个识别游离赖氨酸的酶。
Nα‐acetyl‐α‐lysine was found as a new type of compatible solutes that acted as an organic cytoprotectant in the strain of Salinicoccus halodurans H3B36. A novel lysine Nα‐acetyltransferase gene (shkat), encoding an enzyme that catalysed the acetylation of lysine exclusively at α position, was identified from this moderate halophilic strain and expressed in Escherichia coli. Sequence analysis indicated ShKAT contained a highly conserved pyrophosphate‐binding loop (Arg‐Gly‐Asn‐Gly‐Asn‐Gly), which was a signature of the GNAT superfamily. ShKAT exclusively recognized free amino acids as substrate, including lysine and other basic amino acids. The enzyme showed a wide range of optimal pH value and was tolerant to high‐alkali and high‐salinity conditions. As a new member of the GNAT superfamily, the ShKAT was the first enzyme recognized free lysine as substrate. We believe this work gives an expanded perspective of the GNAT superfamily, and reveals great potential of the shkat gene to be applied in genetic engineering for resisting extreme conditions. A novel lysine Nα‐acetyltransferase gene (shkat), encoding an enzyme that catalyzed the acetylation of lysine exclusively at α position, was identified from Salinicoccus halodurans H3B36 and expressed in Escherichia coli. Sequence analysis indicated ShKAT contained a highly conserved pyrophosphate binding loop (Arg‐Gly‐Asn‐Gly‐Asn‐Gly), which was a signature of the GNAT superfamily. ShKAT exclusively recognized free amino acids as substrate, and was the first enzyme recognized free lysine in GNAT superfamily.