1.13.11.66	additional information	active site structure analysis, apo or with bound substrate methylhydroquinone, overview	-, 744430	
1.13.11.66	physiological function	hydroquinone 1,2-dioxygenase PnpCD is the key enzyme in the hydroquinone pathway of para-nitrophenol degradation, catalyzes the ring cleavage of hydroquinone to gamma-hydroxymuconic semialdehyde	745331	
1.13.11.66	physiological function	the enzyme YaiA plays a key role in alleviating quinone/copper stress. The yahCD-yaiAB operon of Lactococcus lactis IL1403 provides resistance to combined copper/quinone stress. The operon is under the control of CopR, which also regulates expression of the copRZA copper resistance operon as well as other Lactococcus lactis genes. Expression of the yahCD-yaiAB operon is induced by copper but not by quinones. Copper induction of the yahCD-yaiAB operon offers protection to copper/quinone toxicity and can provide a growth advantage to Lactococcus lactis in some environments. Regulation of quinone degradation by CopR thus appears to be a hallmark of Lactococci. The conversion of hydroquinone to 4-hydroxymuconic semialdehyde by the YaiA dioxygenase appears to be too slow for acute detoxification, but probably serves as long-term remedy by degrading the hydroquinone pool, which constitutes a reservoir for the formation of toxic pbenzoquinones by spontaneous oxidation that is greatly accelerated by copper	-, 745802	
1.13.11.66	additional information	the PnpCD structure contains a pseudo cupin and a iron metallocenter in the catalytic PnpD, which adds to understanding of the ring cleavage mechanism of dioxygenases, structure analysis, overview	745331	
1.13.11.66	metabolism	the two-subunit hydroquinone 1,2-dioxygenase PnpCD is the ring cleavage enzyme in para-nitrophenol catabolism	745331