To gain a better understanding of the molec-ular mechanisms of photosystem!(PSI)biogenesis,wecharacterized the Arabidopsis thaliana photosystem l bio-genesis factor 2(pbf2)mutant,which lacks PSl complex.PBF2 encodes a...To gain a better understanding of the molec-ular mechanisms of photosystem!(PSI)biogenesis,wecharacterized the Arabidopsis thaliana photosystem l bio-genesis factor 2(pbf2)mutant,which lacks PSl complex.PBF2 encodes a P-class pentatricopeptide repeat(PPR)protein.In the pbf2 mutants,we observed a striking de-crease in the transcript level of only one gene,thechloroplast gene ycf3,which is essential for PSl assembly.Further analysis of ycf3 transcripts showed that PBF2 isspecifically required for the splicing of ycf3 intron 1.Computational prediction of binding sequences and elec-trophoretic mobility shift assays reveal that PBF2 specifi-cally binds to a sequence in ycf3 intron 1.Moreover,we found that PBF2 interacted with two general factors forgroup ll intron splicing CHLOROPLAST RNA SPLICING2-AsSOCIATED FACTOR1(CAF1)and CAF2,and facilitated theassociation of these two factors with ycf3 intron 1.Ourresults suggest that PBF2 is specifically required for thesplicing of ycf3 intron 1 through cooperating with CAF1and CAF2.Our results also suggest that additional proteinsare required to contribute to the specificity of CAF-dependent group ll intron splicing.展开更多
基金This work was supported by the National Natural Science Foundation of China(reference numbers 31730102 and 31401035)the Key Research Plan of Frontier Sciences of the Chinese Academy of Sciences(reference number QYZDJ-SSW-SMC003)。
文摘To gain a better understanding of the molec-ular mechanisms of photosystem!(PSI)biogenesis,wecharacterized the Arabidopsis thaliana photosystem l bio-genesis factor 2(pbf2)mutant,which lacks PSl complex.PBF2 encodes a P-class pentatricopeptide repeat(PPR)protein.In the pbf2 mutants,we observed a striking de-crease in the transcript level of only one gene,thechloroplast gene ycf3,which is essential for PSl assembly.Further analysis of ycf3 transcripts showed that PBF2 isspecifically required for the splicing of ycf3 intron 1.Computational prediction of binding sequences and elec-trophoretic mobility shift assays reveal that PBF2 specifi-cally binds to a sequence in ycf3 intron 1.Moreover,we found that PBF2 interacted with two general factors forgroup ll intron splicing CHLOROPLAST RNA SPLICING2-AsSOCIATED FACTOR1(CAF1)and CAF2,and facilitated theassociation of these two factors with ycf3 intron 1.Ourresults suggest that PBF2 is specifically required for thesplicing of ycf3 intron 1 through cooperating with CAF1and CAF2.Our results also suggest that additional proteinsare required to contribute to the specificity of CAF-dependent group ll intron splicing.
