This region encompasses much of the RNA and SrmB binding motifs on polymerase A.

1: Poly(A) polymerase I of Escherichia coli: characterization of the catalytic domain, an RNA binding site and regions for the interaction with proteins involved in mRNA degradation. Raynal LC, Carpousis AJ; Mol Microbiol. 1999;32:765-775. PMID:10361280