5MEF

Cyanothece lipoxygenase 2 (CspLOX2) variant - L304F

Summary for 5MEF

• Entry DOI: 10.2210/pdb5mef/pdb
• Descriptor: Arachidonate 15-lipoxygenase, FE (III) ION, GLYCEROL, ... (6 entities in total)
• Functional Keywords: linoleate 11-lipoxygenase, oxidoreductase
• Biological source: Cyanothece sp. (strain PCC 8801)
• Total number of polymer chains: 2
• Total formula weight: 130115.01

Authors

Newie, J.,Neumann, P.,Werner, M.,Mata, R.A.,Ficner, R.,Feussner, I. (deposition date: 2016-11-14, release date: 2017-05-31, Last modification date: 2024-01-17)

Primary citation

Newie, J.,Neumann, P.,Werner, M.,Mata, R.A.,Ficner, R.,Feussner, I.
Lipoxygenase 2 from Cyanothece sp. controls dioxygen insertion by steric shielding and substrate fixation.
Sci Rep, 7:2069-2069, 2017

PubMed Abstract: The biological function of lipoxygenases depends on the regio and stereo specific formation of fatty acid-derived hydroperoxides and different concepts exist to explain the mechanism that directs dioxygen to a specific carbon atom within the substrate. Here, we report the 1.8 Å resolution crystal structure of a cyanobacterial lipoxygenase that produces bis-allylic hydroperoxides (CspLOX2). Site directed mutagenesis experiments combined with computational approaches reveal that residues around the active site direct dioxygen to a preferred carbon atom and stereo configuration in the substrate fatty acid. Modulating the cavity volume around the pentadiene system of linoleic acid shifted the product formation towards 9S-, 9R-, 13S- or 13R-hydroperoxides in correlation with the site of mutation, thus decreasing the amount of the bis-allylic 11R-hydroperoxide. Decreasing the channel size of a 9R-lipoxygenase (CspLOX1) on the other hand could in turn induce formation of the bis-allylic 11R-hydroperoxide. Together this study suggests that an active site clamp fixing the pentadiene system of the substrate together with steric shielding controls the stereo and regio specific positioning of dioxygen at all positions of the reacting pentadiene system of substrate fatty acids.

PubMed: 28522865
DOI: 10.1038/s41598-017-02153-w

Experimental method

X-RAY DIFFRACTION (2.357 Å)