Table 1. Factors Demonstrated or Suggested to Facilitate Translation of Specific Transcripts in Seed Plant Plastids.

Factor	Protein Domain(s)	Reading Frames with Translation Promoted	Species	References for Translational Function
ATP1	Unknown	atpB	Maize	McCormac and Barkan (1999); Zoschke et al. (2013a)
ATP4/SVR7	PPR, SMR	atpB	Maize, Arabidopsis	Zoschke et al. (2012)
CRP1	PPR	petA, petD*, psaC	Maize	Barkan et al. (1994); Zoschke et al. (2013a)
CRR2	PPR	ndhB*	Arabidopsis	Hashimoto et al. (2003)
HCF107	HAT	psbH*	Arabidopsis	Felder et al. (2001); Hammani et al. (2012)
HCF152	PPR	petB*?	Arabidopsis	Meierhoff et al. (2003)
HCF173	Atypical SDR	psbA*	Arabidopsis	Schult et al. (2007)
HCF244	Atypical SDR	psbA	Arabidopsis	Link et al. (2012)
PGR3	PPR	petL*, ndhA?	Arabidopsis	Yamazaki et al. (2004); Cai et al. (2011)
PPR10	PPR	atpH*	Maize	Pfalz et al. (2009); Prikryl et al. (2011); Zoschke et al. (2013a)
PPR53	PPR, SMR	ndhA*	Maize, Arabidopsis	Zoschke et al. (2016)

Asterisks indicate an additional function in stabilization of the transcript 5′ end upstream of the reading frame whose translation is stimulated. Question marks denote proposed but experimentally unconfirmed functions in stimulation of translation. SDR, short-chain dehydrogenase/reductase; HAT, half a tetratricopeptide repeat; SMR, small MutS-related.