bioRxiv preprint doi: https://doi.org/10.1101/2020.01.08.898148; this version posted January 9, 2020. The copyright holder for this preprint (which was not certified by peer review) is the author/funder. All rights reserved. No reuse allowed without permission. 1 Title: 2 Catabolism of 3-hydroxypyridine by Ensifer adhaerens HP1: a novel four-component 3 gene encoding 3-hydroxypyridine dehydrogenase HpdA catalyzes the first step of 4 biodegradation 5 6 Running title: 7 Microbial 3-hydroxypyridine degradation 8 9 Authors: 10 Haixia Wang a, Xiaoyu Wang a, Hao Ren a, Xuejun Wang a, Zhenmei Lu a# 11 12 a MOE Laboratory of Biosystem Homeostasis and Protection, College of Life Sciences, 13 Zhejiang University, Hangzhou, China 14 15 #Address correspondence to Zhenmei Lu,
[email protected] 16 17 18 19 20 21 22 23 1 bioRxiv preprint doi: https://doi.org/10.1101/2020.01.08.898148; this version posted January 9, 2020. The copyright holder for this preprint (which was not certified by peer review) is the author/funder. All rights reserved. No reuse allowed without permission. 24 Abstract 25 3-Hydroxypyridine (3HP) is an important natural pyridine derivative. Ensifer 26 adhaerens HP1 can utilize 3HP as the sole source of carbon, nitrogen and energy to 27 grow. However, the genes responsible for the degradation of 3HP remain unknown. In 28 this study, we predicted that a gene cluster, designated 3hpd, may be responsible for the 29 degradation of 3HP. The initial hydroxylation of 3HP is catalyzed by a four-component 30 dehydrogenase (HpdA1A2A3A4), leading to the formation of 2,5-dihydroxypyridine 31 (2,5-DHP) in E.