서강대학교

초록/요약

A variety of light-driven ion-pumping rhodopsins was ubiquitously distributed all of three domains. Among those rhodopsins, proton-pumping rhodopsins can convert light energy to potential biochemical energy, without gas or assistant protein. It had been suggested that not only this rhodopsin phototrophy is advantageous, but the simple requirement of a set of genes for rhodopsin activation necessarily had enabled successful lateral gene transfer of a set of genes between species. Consistent with this abundance of rhodopsin phototrophy among microorganisms, microorganisms sampled from the Vietnam local water environments(VLWs) contain various variants of proton-pumping rhodopsins. Tentative rhodopsins in this study are considered as belonging to bacteroidetes phylum with no exceptions after phylogenetic analysis. These rhodopsins were characterized biophysically, through the chimeric expression strategy. These rhodopsins exhibited characteristics similar to green-light absorbing proteorhodopsin. Taken together, VLWs harbor diverse microorganisms affiliated within phylum bacteroidetes, which exploit proton pumping rhodopsin for using prevailing light at the surface of the aquatic environment to energy conversion. Additionally, I suggest that there are significant differences between canonical proteobacteria-derived PR (PPR) and bacteroidetes-derived PR (BDR), including that BDRs share potential to accommodate additional cofactor.