Plant organellar DNA primase-helicase synthesizes RNA primers for organellar DNA polymerases using a unique recognition sequence.

ABSTRACT: DNA primases recognize single-stranded DNA (ssDNA) sequences to synthesize RNA primers during lagging-strand replication. Arabidopsis thaliana encodes an ortholog of the DNA primase-helicase from bacteriophage T7, dubbed AtTwinkle, that localizes in chloroplasts and mitochondria. Herein, we report that AtTwinkle synthesizes RNA primers from a 5'-(G/C)GGA-3' template sequence. Within this sequence, the underlined nucleotides are cryptic, meaning that they are essential for template recognition but are not instructional during RNA synthesis. Thus, in contrast to all primases characterized to date, the sequence recognized by AtTwinkle requires two nucleotides (5'-GA-3') as a cryptic element. The divergent zinc finger binding domain (ZBD) of the primase module of AtTwinkle may be responsible f

SUBMITTER: Peralta-Castro A 

PROVIDER: S-EPMC5737085 | biostudies-literature | 2017 Oct

REPOSITORIES: biostudies-literature