Protein synthesis features shared by Archaea and Eukarya: which statement is correct for both domains?

Introduction / Context:
Archaea share several molecular features with Eukarya despite their prokaryotic cell organization. One well-tested distinction in exams is sensitivity of the translational machinery to specific inhibitors such as diphtheria toxin.

Given Data / Assumptions:

• Diphtheria toxin targets elongation factor 2 (EF-2/eEF-2) activity.
• We compare core translation features across Archaea, Bacteria, and Eukarya.
• We must find a statement true for both Archaea and Eukarya.

Concept / Approach:
Diphtheria toxin inactivates eukaryotic-type elongation factor (EF-2). Archaeal translation factors and ribosomal components resemble eukaryotic counterparts more than bacterial ones, making archaeal translation similarly sensitive. In contrast, Bacteria use EF-G and are not inhibited by the toxin.

Step-by-Step Solution:

Verification / Alternative check:
Compare the composition of ribosomal proteins and initiation/elongation factors across domains—archaeal factors cluster with eukaryotic homologs phylogenetically.

Why Other Options Are Wrong:
A: Not true for eukaryotes. C: Contradicts universal L-amino acid usage. D: fMet is bacterial only.

Common Pitfalls:
Assuming all prokaryotes share bacterial-like translation features; Archaea often align with Eukarya in core information-processing proteins.

Final Answer:
translation is inhibited by diphtheria toxin