Identification of genes encoding photoconvertible (Class I) water-soluble chlorophyll-binding proteins from Chenopodium ficifolium

Abstract

Photoconvertible water-soluble chlorophyll-binding proteins, called Class I WSCPs, have been detected in Chenopodiaceae, Amaranthaceae and Polygonaceae plant species. To date, Chenopodium album WSCP (CaWSCP) is the only cloned gene encoding a Class I WSCP. In this study, we identified two cDNAs encoding Chenopodium ficifolium Class I WSCPs, CfWSCP1, and CfWSCP2. Sequence analyses revealed that the open reading frames of CfWSCP1 and CfWSCP2 were 585 and 588 bp, respectively. Furthermore, both CfWSCPs contain cystein2 and cystein30, which are essential for the chlorophyll-binding ability of CaWSCP. Recombinant CfWSCP1 and CfWSCP2, expressed in Escherichia coli as hexa-histidine fusion proteins (CfWSCP1-His and CfWSCP2-His), formed inclusion bodies; however, we were able to solubilize these using a buffer containing 8 M urea and then refold them by dialysis. The refolded CfWSCP1-His and CfWSCP2-His could bind chlorophylls and exhibited photoconvertibility, confirming that the cloned CfWSCPs are further examples of Class I WSCPs.

Are tyrosine residues involved in the photoconversion of the water‐soluble chlorophyll‐binding protein ofChenopodium album?

“…Subsequently, similar photoconvertible WSCPs were isolated from various plants of Chenopodiaceae, Amaranthaceae and Polygonaceae (Takamiya ; Takahashi et al . ). In addition to these photoconvertible WSCPs, Murata et al .…”

“…Class I WSCPs are members of the Domain Unknown Function (DUF) 538 superfamily (Takahashi et al . , ), while Class II WSCPs are members of the Kunitz‐type trypsin inhibitor family (Satoh et al . ; Bektas et al .…”

“…Chenopodium album WSCP (CaWSCP) had a unique photoconvertibility. Subsequently, similar photoconvertible WSCPs were isolated from various plants of Chenopodiaceae, Amaranthaceae and Polygonaceae (Takamiya 1973;Takahashi et al 2014a). In addition to these photoconvertible WSCPs, found a non-photoconvertible WSCP in cauliflower (Brassica oleracea var.…”

“…Class I WSCPs are members of the Domain Unknown Function (DUF) 538 superfamily (Takahashi et al 2013b(Takahashi et al , 2014a, while Class II WSCPs are members of the Kunitz-type trypsin inhibitor family (Satoh et al 1998;Bektas et al 2012;Takahashi et al 2012Takahashi et al , 2013a. There is no homology between Class I and Class II WSCPs.…”

Effect of near-infrared irradiation on photoconversion of the water-soluble chlorophyll-binding protein ofChenopodium album

“…2−4) Based on their photoconvertibility, WSCPs can be categorized into two classes, Class I (photoconvertible type) and Class II (non-photoconvertible type). 1) Sequence analyses revealed that Chenopodium album WSCP (CaWSCP), a Class I WSCP, is a member of the domain unknown function 538 superfamily 5,6) while all Class II WSCPs belong to the Kunitz-type trypsin inhibitor family. 1,3,7−10) There have been various studies on the biochemical and physicochemical properties of Class I WSCPs, including CaWSCP.…”