TY - JOUR

T1 - The First Poly(A) Polymerase from Alphaproteobacteria

AU - Oscorbin, Igor P.

AU - Kunova, Maria S.

AU - Filipenko, Maxim L.

N1 - Oscorbin, I. P. The First Poly(A) Polymerase from Alphaproteobacteria / I. P. Oscorbin, M. S. Kunova, M. L. Filipenko // International Journal of Molecular Sciences. – 2026. – Vol. 27, No. 5. – P. 2467. – DOI 10.3390/ijms27052467. – EDN YYPMNU. This research and the APC were funded by the Russian Science Foundation, grant number 24-24-00389, https://rscf.ru/project/24-24-00389/ (accessed on 3 December 2025).

PY - 2026/3/7

Y1 - 2026/3/7

N2 - Bacterial poly(A) polymerases (PAPs) play an important role in RNA metabolism but remain poorly characterized outside Gammaproteobacteria. Here, we cloned and biochemically characterized the first PAP from Alphaproteobacteria, specifically from Marinobacter lipolyticus (Mli PAP). Using homology-based screening against E. coli PAP-1, we identified Mli PAP, sharing 54.8% sequence identity with its E. coli counterpart. The enzyme was expressed in E. coli but formed insoluble inclusion bodies; the active enzyme was purified as a fusion protein with the DsbA protein and used for functional assays. Mli PAP exhibited optimal activity at 30 °C and similar thermostability to E. coli PAP-1. ATP was the preferred substrate, with Km comparable to E. coli PAP-1 (1.61 mM and 1.70 mM, respectively), and Mg2+ (10 mM) was identified as the optimal cofactor. Mli PAP displayed salt-dependent activity, with the most effective polyadenylation in KCl and inhibition by NaCl and ammonium salts, contrasting with the halophilic nature of its host. This study provides the first functional insights into PAPs from Alphaproteobacteria, broadening the understanding of PAP diversity and biochemical properties, as well as the potential applications of PAPs in biotechnology.

AB - Bacterial poly(A) polymerases (PAPs) play an important role in RNA metabolism but remain poorly characterized outside Gammaproteobacteria. Here, we cloned and biochemically characterized the first PAP from Alphaproteobacteria, specifically from Marinobacter lipolyticus (Mli PAP). Using homology-based screening against E. coli PAP-1, we identified Mli PAP, sharing 54.8% sequence identity with its E. coli counterpart. The enzyme was expressed in E. coli but formed insoluble inclusion bodies; the active enzyme was purified as a fusion protein with the DsbA protein and used for functional assays. Mli PAP exhibited optimal activity at 30 °C and similar thermostability to E. coli PAP-1. ATP was the preferred substrate, with Km comparable to E. coli PAP-1 (1.61 mM and 1.70 mM, respectively), and Mg2+ (10 mM) was identified as the optimal cofactor. Mli PAP displayed salt-dependent activity, with the most effective polyadenylation in KCl and inhibition by NaCl and ammonium salts, contrasting with the halophilic nature of its host. This study provides the first functional insights into PAPs from Alphaproteobacteria, broadening the understanding of PAP diversity and biochemical properties, as well as the potential applications of PAPs in biotechnology.

KW - Marinobacter lipolyticus

KW - PAP

KW - pcnB

KW - polyA-polymerase

KW - polyadenylation

KW - pcnB

KW - поли(А)-полимераза

KW - PAP

KW - полиаденилирование

KW - Marinobacter lipolyticus

UR - https://www.mendeley.com/catalogue/128ded5e-e9ec-32cf-aa17-808593d4118b/

UR - https://www.scopus.com/pages/publications/105032697472

UR - https://elibrary.ru/item.asp?id=90100130

U2 - 10.3390/ijms27052467

DO - 10.3390/ijms27052467

M3 - Article

C2 - 41828684

VL - 27

JO - International Journal of Molecular Sciences

JF - International Journal of Molecular Sciences

SN - 1661-6596

IS - 5

M1 - 2467

ER -