TY - JOUR
T1 - A transducer for microbial sensory rhodopsin that adopts GTG as a start codon is identified in Haloarcula marismortui
AU - Fu, Hsu Yuan
AU - Lu, Yen Hsu
AU - Yi, Hsiu Ping
AU - Yang, Chii Shen
N1 - Funding Information:
We thank Tai-He Yang (Giant Lion Know-How Co., Ltd., Taiwan) for funding.
Copyright:
Copyright 2013 Elsevier B.V., All rights reserved.
PY - 2013/4/5
Y1 - 2013/4/5
N2 - Microbial sensory rhodopsins are known to mediate phototaxis, and all of the known sensory rhodopsins execute this function with a specific cognate transducer that has two-transmembrane (2-TM) regions. In the genome of Haloarcula marismortui, a total of six rhodopsin genes were annotated, and we previously showed three of them to be the ion type and suggested the other three as sensory type, even though the candidate transducer gene, htr, for HmSRI was missing the 2-TM region that is found in all of the other known transducers. Here we showed this htr gene featured a preceding 2-TM region when the alternative start codon GTG located 291 nucleotides upstream of the original annotated open reading frame (ORF) was introduced and it is named as htrI in this study. Overexpression of HmHtrI exhibited it existed as a membrane protein and several biophysical assays confirmed it functionally interacted with HmSRI. Together with our previous reverse-transcriptase-PCR results and phototaxis measurements, the new ORF of original predicted soluble htr gene product was a membrane protein with a 2-TM region, HmHtrI; and it serves as the cognate transducer for HmSRI. HmHtrI therefore is the first transducer for the sensory rhodopsin adopted start codon other than ATG.
AB - Microbial sensory rhodopsins are known to mediate phototaxis, and all of the known sensory rhodopsins execute this function with a specific cognate transducer that has two-transmembrane (2-TM) regions. In the genome of Haloarcula marismortui, a total of six rhodopsin genes were annotated, and we previously showed three of them to be the ion type and suggested the other three as sensory type, even though the candidate transducer gene, htr, for HmSRI was missing the 2-TM region that is found in all of the other known transducers. Here we showed this htr gene featured a preceding 2-TM region when the alternative start codon GTG located 291 nucleotides upstream of the original annotated open reading frame (ORF) was introduced and it is named as htrI in this study. Overexpression of HmHtrI exhibited it existed as a membrane protein and several biophysical assays confirmed it functionally interacted with HmSRI. Together with our previous reverse-transcriptase-PCR results and phototaxis measurements, the new ORF of original predicted soluble htr gene product was a membrane protein with a 2-TM region, HmHtrI; and it serves as the cognate transducer for HmSRI. HmHtrI therefore is the first transducer for the sensory rhodopsin adopted start codon other than ATG.
KW - Alternative start codon
KW - Gene locus
KW - Sensory rhodopsin
KW - Transducer
KW - Transmembrane domain
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U2 - 10.1016/j.jphotobiol.2013.02.002
DO - 10.1016/j.jphotobiol.2013.02.002
M3 - Article
C2 - 23474528
AN - SCOPUS:84874596046
SN - 1011-1344
VL - 121
SP - 15
EP - 22
JO - Journal of Photochemistry and Photobiology B: Biology
JF - Journal of Photochemistry and Photobiology B: Biology
ER -