4ADV

Structure of the E. coli methyltransferase KsgA bound to the E. coli 30S ribosomal subunit

Summary for 4ADV

• Entry DOI: 10.2210/pdb4adv/pdb
• Related: 1M5G 1MJ1 1P6G 1P87 1QYR 1S03 1ZN1 2AVY 2AW7 2VHO 2VHP 2WWL 4A2I
• EMDB information: 2017
• Descriptor: 16S RIBOSOMAL RNA, 30S RIBOSOMAL PROTEIN S10, 30S RIBOSOMAL PROTEIN S11, ... (23 entities in total)
• Functional Keywords: translation, ribosome biogenesis, small ribosomal subunit
• Biological source: ESCHERICHIA COLI; More
• Cellular location: Cytoplasm : P06992
• Total number of polymer chains: 22
• Total formula weight: 815557.47

Authors

Boehringer, D.,O'Farrell, H.C.,Rife, J.P.,Ban, N. (deposition date: 2012-01-03, release date: 2012-02-15, Last modification date: 2024-05-08)

Primary citation

Boehringer, D.,O'Farrell, H.C.,Rife, J.P.,Ban, N.
Structural Insights Into Methyltransferase Ksga Function in 30S Ribosomal Subunit Biogenesis
J.Biol.Chem., 287:10453-10459, 2012

PubMed Abstract: The assembly of the ribosomal subunits is facilitated by ribosome biogenesis factors. The universally conserved methyltransferase KsgA modifies two adjacent adenosine residues in the 3'-terminal helix 45 of the 16 S ribosomal RNA (rRNA). KsgA recognizes its substrate adenosine residues only in the context of a near mature 30S subunit and is required for the efficient processing of the rRNA termini during ribosome biogenesis. Here, we present the cryo-EM structure of KsgA bound to a nonmethylated 30S ribosomal subunit. The structure reveals that KsgA binds to the 30S platform with the catalytic N-terminal domain interacting with substrate adenosine residues in helix 45 and the C-terminal domain making extensive contacts to helix 27 and helix 24. KsgA excludes the penultimate rRNA helix 44 from adopting its position in the mature 30S subunit, blocking the formation of the decoding site and subunit joining. We suggest that the activation of methyltransferase activity and subsequent dissociation of KsgA control conformational changes in helix 44 required for final rRNA processing and translation initiation.

PubMed: 22308031
DOI: 10.1074/JBC.M111.318121

Experimental method

ELECTRON MICROSCOPY (13.5 Å)