RT Journal Article
SR Electronic
T1 Cyanophage-encoded lipid-desaturases: oceanic distribution, diversity and function
JF bioRxiv
FD Cold Spring Harbor Laboratory
SP 109157
DO 10.1101/109157
A1 Sheila Roitman
A1 Ellen Hornung
A1 José Flores-Uribe
A1 Itai Sharon
A1 Ivo Feussner
A1 Oded Béjà
YR 2017
UL http://biorxiv.org/content/early/2017/02/16/109157.abstract
AB Cyanobacteria are among the most abundant photosynthetic organisms in the oceans; viruses infecting cyanobacteria (cyanophages) can alter cyanobacterial populations, and therefore affect the local food web and global biochemical cycles. These phages carry auxiliary metabolic genes (AMGs), which rewire various metabolic pathways in the infected host cell, resulting in increased phage fitness. Coping with stress resulting from photodamage appears to be a central necessity of cyanophages, yet the overall mechanism is poorly understood. Here we report a novel, widespread cyanophage AMG, encoding a fatty acid desaturase (FAD), found in two genotypes with distinct geographical distribution. FADs are capable of modulating the fluidity of the host’s membrane, a fundamental stress response in living cells. We show that both viral fatty acid desaturases (vFADs) families are Δ9 lipid desaturases, catalyzing the desaturation at carbon 9 in C16 fatty acid chains. In addition, we present the first fatty acid profiling for marine cyanobacteria, which suggests a unique desaturation pathway of medium to long chain fatty acids no longer than C16, in accordance to the vFADs activity. Our findings suggest that cyanophages fiddle with the infected host’s cell, leading to increased photoprotection and potentially enhancing viral-encoded photosynthetic proteins, resulting in a new viral metabolic network.