Analysis and Phylogeny of Small Heat Shock Proteins from Marine Viruses and Their Cyanobacteria Host |
| |
| Authors: | Halim Maaroufi Robert M Tanguay |
| |
| Institution: | 1. Plate-forme de bio-informatique and Institut de biologie intégrative et des systèmes (IBIS), Université Laval, Quebec, Canada.; 2. Laboratory of Cellular and Developmental Genetics, Department of Molecular Biology, Medical Biochemistry and Pathology, IBIS and PROTEO, Université Laval, Quebec, Canada.; University of Arkansas for Medical Sciences, United States of America, |
| |
| Abstract: | Small heat shock proteins (sHSPs) are oligomeric stress proteins characterized by an α-crystallin domain (ACD) surrounded by a N-terminal arm and C-terminal extension. Publications on sHSPs have reported that they exist in prokaryotes and eukaryotes but, to our knowledge, not in viruses. Here we show that sHSPs are present in some cyanophages that infect the marine unicellular cyanobacteria, Synechococcus and Prochlorococcus. These phage sHSPs contain a conserved ACD flanked by a relatively conserved N-terminal arm and a short C-terminal extension with or without the conserved C-terminal anchoring module (CAM) L-X-I/V, suggested to be implicated in the oligomerization. In addition, cyanophage sHSPs have the signature pattern, P-P-YF]-N-ILV]-IV]-x(9)-EQ], in the predicted β2 and β3 strands of the ACD. Phylogenetically, cyanophage sHSPs form a monophyletic clade closer to bacterial class A sHSPs than to cyanobacterial sHSPs. Furthermore, three sHSPs from their cellular host, Synechococcus, are phylogenetically close to plants sHSPs. Implications of evolutionary relationships between the sHSPs of cyanophages, bacterial class A, cyanobacteria, and plants are discussed. |
| |
| Keywords: | |
|
|
