Bypassing rRNA methylation by RsmA/Dim1during ribosome maturation in the hyperthermophilic archaeon Nanoarchaeum equitans

TY - JOUR

T1 - Bypassing rRNA methylation by RsmA/Dim1during ribosome maturation in the hyperthermophilic archaeon Nanoarchaeum equitans

AU - Seistrup, Kenneth H

AU - Rose, Simon

AU - Birkedal, Ulf

AU - Nielsen, Henrik

AU - Huber, Harald

AU - Douthwaite, Stephen

N1 - © The Author(s) 2016. Published by Oxford University Press on behalf of Nucleic Acids Research.

PY - 2017/2/28

Y1 - 2017/2/28

N2 - In all free-living organisms a late-stage checkpoint in the biogenesis of the small ribosomal subunit involves rRNA modification by an RsmA/Dim1 methyltransferase. The hyperthermophilic archaeon Nanoarchaeum equitans, whose existence is confined to the surface of a second archaeon, Ignicoccus hospitalis, lacks an RsmA/Dim1 homolog. We demonstrate here that the I. hospitalis host possesses the homolog Igni_1059, which dimethylates the N(6)-positions of two invariant adenosines within helix 45 of 16S rRNA in a manner identical to other RsmA/Dim1 enzymes. However, Igni_1059 is not transferred from I. hospitalis to N. equitans across their fused cell membrane structures and the corresponding nucleotides in N. equitans 16S rRNA remain unmethylated. An alternative mechanism for ribosomal subunit maturation in N. equitans is suggested by sRNA interactions that span the redundant RsmA/Dim1 site to introduce 2'-O-ribose methylations within helices 44 and 45 of the rRNA.

AB - In all free-living organisms a late-stage checkpoint in the biogenesis of the small ribosomal subunit involves rRNA modification by an RsmA/Dim1 methyltransferase. The hyperthermophilic archaeon Nanoarchaeum equitans, whose existence is confined to the surface of a second archaeon, Ignicoccus hospitalis, lacks an RsmA/Dim1 homolog. We demonstrate here that the I. hospitalis host possesses the homolog Igni_1059, which dimethylates the N(6)-positions of two invariant adenosines within helix 45 of 16S rRNA in a manner identical to other RsmA/Dim1 enzymes. However, Igni_1059 is not transferred from I. hospitalis to N. equitans across their fused cell membrane structures and the corresponding nucleotides in N. equitans 16S rRNA remain unmethylated. An alternative mechanism for ribosomal subunit maturation in N. equitans is suggested by sRNA interactions that span the redundant RsmA/Dim1 site to introduce 2'-O-ribose methylations within helices 44 and 45 of the rRNA.

U2 - 10.1093/nar/gkw839

DO - 10.1093/nar/gkw839

M3 - Journal article

C2 - 28204608

SN - 0305-1048

VL - 45

SP - 2007

EP - 2015

JO - Nucleic Acids Research

JF - Nucleic Acids Research

IS - 4

ER -