Figure 6.

Isolation of mca1 and tca1 mutants using cell line T1, in which CrCD and cytochrome f are expressed under the control of the petA promoter and 5′ UTR. (a) Identification of light-sensitive UV mutants of T1. Thirty 5-FC-resistant colonies from the UV mutagenesis screen were spotted onto two TAP agar plates and incubated in the dark or under 50 μE m⁻² sec⁻¹ light. Ten of the mutants, indicated by shaded squares on the strain key (right), showed poor growth in the light, and were analysed by PCR and DNA sequencing of the MCA1 and TCA1 genes to identify any mutations. (b) Nuclear mutations identified in the ten light-sensitive UV mutants of cell line T1.