Significance
Phototrophic organisms worldwide produce estimated 10 gigatons of sulfoquinovose (SQ) per year; hence, complete degradation of SQ by bacteria is an important part of the biogeochemical sulfur cycle. Here, we show that
Pseudomonas putida
SQ1 catabolizes SQ to 3-sulfolactate (SL) in analogy to the Entner–Doudoroff pathway for glucose-6-phosphate, involving five newly discovered reactions, enzymes, and genes, and three newly discovered organosulfur intermediates. The SL can be mineralized by other bacteria, thus closing the sulfur cycle within a bacterial community. The genes for the SQ Entner–Doudoroff pathway can be found in genomes of a wide range of Proteobacteria, which shows that SQ utilization is a widespread and important, but still underrecognized, trait of bacteria in all environments where SQ is produced and degraded.
意义
全球光合生物每年产生约10千亿吡烯醇磺醇(SQ),因此,细菌对SQ的完全降解是生物地球化学硫循环的重要部分。在这里,我们展示了Pseudomonas putida SQ1类似于葡萄糖-6-磷酸的恩特纳-道杜夫途径,通过五个新发现的反应、酶和基因,以及三个新发现的有机硫中间体,将SQ降解为3-磺酸内酯(SL)。SL可以被其他细菌矿化,从而在细菌群落内完成硫循环。 SQ恩特纳-道杜夫途径的基因可以在广泛的变形菌类基因组中找到,这表明SQ利用是在产生和降解SQ的所有环境中广泛而重要的,但仍未被充分认识的细菌特征。