Functional consequences of N- or C-terminal deletions of the delta subunit of chloroplast ATP synthase.
Mutagenesis was used to generate seven truncation mutants of the spinach (Spinacia oleracea) chloroplast ATP synthase delta subunit lacking 5, 11, 17, or 35 amino acid residues from the N-terminus or 3, 9, or 15 residues from the C-terminus. Interactions between these mutants and all other subunits of the chloroplast ATPase were investigated by a yeast two-hybrid system. The results indicate that the N-terminal deletions mainly affected interactions between the delta subunit and the other part of CF(1), but did not significantly affect interactions with the CF(0) sector. In contrast, C-terminal truncations of the delta subunit mainly affected its interaction with the CF(0) sector and caused little impairment in interactions with the other part of CF(1). The conformation of the delta subunit C-terminal domain seems to be more sensitive to the truncations, as shown by minimal expression driven by C-terminal deleted (nine residues) mutants. Further studies showed C-terminal truncations of the delta subunit greatly impaired its ability to restore cyclic photophosphorylation in NaBr vesicles, whereas N-terminal truncations had little effect on the ability of delta to plug the CF(0) channel. None of the mutants impaired ATP hydrolysis by CF(1).
Ni
Zhang-Lin
ZL
Shanghai Institute of Plant Physiology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 300 Fenglin Road, Shanghai 200032, China.
Shi
Xiao-Bing
XB
Wei
Jia-Mian
JM
D000595:Amino Acid Sequence; D001965:Bromides / Q000737:chemistry; D002736:Chloroplasts / Q000201:enzymology* / Q000235:genetics; D004926:Escherichia coli / Q000235:genetics; D008969:Molecular Sequence Data; D016296:Mutagenesis; D010446:Peptide Fragments / Q000737:chemistry* / Q000235:genetics; D010766:Phosphorylation; D010940:Plant Proteins / Q000737:chemistry / Q000235:genetics; D017434:Protein Structure, Tertiary / Q000235:genetics; D021122:Protein Subunits / Q000737:chemistry* / Q000235:genetics; D018892:Proton-Motive Force / Q000235:genetics; D006180:Proton-Translocating ATPases / Q000737:chemistry* / Q000235:genetics*; D011994:Recombinant Proteins / Q000096:biosynthesis / Q000737:chemistry; D017384:Sequence Deletion; D017670:Sodium Compounds / Q000737:chemistry; D018724:Spinacia oleracea; D020524:Thylakoids / Q000201:enzymology; D020798:Two-Hybrid System Techniques
D001965:Bromides; D010446:Peptide Fragments; D010940:Plant Proteins; D021122:Protein Subunits; D011994:Recombinant Proteins; D017670:Sodium Compounds; D006180:Proton-Translocating ATPases; C027938:sodium bromide