Table I.

Codon frequency in wild-type and mutant rbcL and atpB segments

rbcL wild type
Codon	AUGa	UCA	CCA	CAA	ACA	GAG	ACU	AAA	GCA	AGU	GUU	GGA	UUC	AAA
Amino acid	Met	Ser	Pro	Gln	Thr	Glu	Thr	Lys	Ala	Ser	Val	Gly	Phe	Lys
Fraction	1.00	0.21	0.24	0.57	0.23	0.38	0.37	0.60	0.29	0.14	0.35	0.24	0.40	0.60
Triplet/1,000	24.6	13.5	10.6	21.0	11.7	12.4	18.4	22.0	18.1	9.3	24.9	17.9	22.5	22.0
rbcL mutant
Codon	AUGa	agu	CCu	CAg	ACA	GAa	ACa	AAA	GCc	uca	GUa	GGA	UUC	AAA
Amino acid	Met	Ser	Pro	Gln	Thr	Glu	Thr	Lys	Ala	Ser	Val	Gly	Phe	Lys
Fraction	1.00	0.14	0.30	0.43	0.23	0.62	0.23	0.60	0.16	0.21	0.31	0.24	0.40	0.60
Triplet/1,000	24.6	9.3	13.5	15.5	11.7	20.7	11.7	22.0	10.1	13.5	21.8	17.9	22.5	22.0
atpB wild type
Codon	AUGa	AGA	AUC	AAU	CCU	ACU	ACU	UCU	GGU	UCU	GGG	GUU	UCC	ACG
Amino acid	Met	Arg	Ile	Asn	Pro	Thr	Thr	Ser	Gly	Ser	Gly	Val	Ser	Thr
Fraction	1.00	0.22	0.27	0.61	0.30	0.37	0.37	0.31	0.38	0.31	0.26	0.35	0.14	0.15
Triplet/1,000	24.6	7.8	15.5	18.1	13.5	18.4	18.4	20.2	28.2	20.2	19.2	24.9	9.1	7.5
atpB mutant
Codon	AUGa	AGA	AUa	AAc	CCg	ACa	ACa	agU	GGa	agU	GGG	GUg	UCC	ACG
Amino acid	Met	Arg	Ile	Asn	Pro	Thr	Thr	Ser	Gly	Ser	Gly	Val	Ser	Thr
Fraction	1.00	0.22	0.29	0.39	0.30	0.23	0.23	0.14	0.24	0.14	0.26	0.21	0.14	0.15
Triplet/1,000	24.6	7.8	16.6	11.4	13.2	11.7	11.7	9.3	17.9	9.3	19.2	15.3	9.1	7.5

^a AUG, Translation initiation codon.