Institute of Food Research, Norwich Research Park, Colney, Norwich NR4 7UA, United Kingdom.
J Biol Chem. 2010 Dec 10;285(50):39224-38. doi: 10.1074/jbc.M110.163154. Epub 2010 Sep 27.
Arginine decarboxylases (ADCs; EC 4.1.1.19) from four different protein fold families are important for polyamine biosynthesis in bacteria, archaea, and plants. Biosynthetic alanine racemase fold (AR-fold) ADC is widespread in bacteria and plants. We report the discovery and characterization of an ancestral form of the AR-fold ADC in the bacterial Chloroflexi and Bacteroidetes phyla. The ancestral AR-fold ADC lacks a large insertion found in Escherichia coli and plant AR-fold ADC and is more similar to the lysine biosynthetic enzyme meso-diaminopimelate decarboxylase, from which it has evolved. An E. coli acid-inducible ADC belonging to the aspartate aminotransferase fold (AAT-fold) is involved in acid resistance but not polyamine biosynthesis. We report here that the acid-inducible AAT-fold ADC has evolved from a shorter, ancestral biosynthetic AAT-fold ADC by fusion of a response regulator receiver domain protein to the N terminus. Ancestral biosynthetic AAT-fold ADC appears to be limited to firmicute bacteria. The phylogenetic distribution of different forms of ADC distinguishes bacteria from archaea, euryarchaeota from crenarchaeota, double-membraned from single-membraned bacteria, and firmicutes from actinobacteria. Our findings extend to eight the different enzyme forms carrying out the activity described by EC 4.1.1.19. ADC gene clustering reveals that polyamine biosynthesis employs diverse and exchangeable synthetic modules. We show that in Bacillus subtilis, ADC and polyamines are essential for biofilm formation, and this appears to be an ancient, evolutionarily conserved function of polyamines in bacteria. Also of relevance to human health, we found that arginine decarboxylation is the dominant pathway for polyamine biosynthesis in human gut microbiota.
精氨酸脱羧酶（ADCs；EC 4.1.1.19）来自四个不同的蛋白质折叠家族，对细菌、古菌和植物中的多胺生物合成至关重要。生物合成丙氨酸消旋酶折叠（AR 折叠）ADC 在细菌和植物中广泛存在。我们报告了在细菌 Chloroflexi 和 Bacteroidetes 门中发现和表征了 AR 折叠 ADC 的原始形式。原始的 AR 折叠 ADC 缺乏大肠杆菌和植物 AR 折叠 ADC 中发现的一个大插入片段，并且与赖氨酸生物合成酶 meso-二氨基庚二酸脱羧酶更相似，它是从后者进化而来的。大肠杆菌酸诱导型 ADC 属于天冬氨酸氨基转移酶折叠（AAT 折叠），参与酸抗性但不参与多胺生物合成。我们在这里报告说，酸诱导型 AAT 折叠 ADC 是通过将响应调节蛋白受体结构域融合到 N 端而从较短的原始生物合成 AAT 折叠 ADC 进化而来的。原始的生物合成 AAT 折叠 ADC 似乎仅限于 Firmicutes 细菌。不同形式的 ADC 的系统发育分布将细菌与古菌、真细菌与古细菌、双层膜细菌与单膜细菌以及放线菌与厚壁菌区分开来。我们的发现将执行 EC 4.1.1.19 描述的活性的不同酶形式扩展到八种。ADC 基因聚类表明，多胺生物合成采用多种可互换的合成模块。我们表明，在枯草芽孢杆菌中，ADC 和多胺对于生物膜形成是必需的，这似乎是多胺在细菌中的古老、进化上保守的功能。与人类健康相关的是，我们发现精氨酸脱羧是人类肠道微生物群中多胺生物合成的主要途径。
