Which of the following statements is true regarding bacterial mRNAs?

• A. Bacterial mRNAs are typically capped at the 5' end with a 7-methylguanosine cap.
• B. Bacterial mRNAs are synthesized and processed in the nucleus before translation.
• C. Bacterial mRNAs are often polycistronic, meaning they can encode multiple proteins from a single transcript.
• D. Bacterial mRNAs have long poly(A) tails that stabilize the transcript.

Answer: (C)

Verified step by step guidance

1. Understand the structure and processing of bacterial mRNA compared to eukaryotic mRNA. Bacterial mRNAs are generally not capped at the 5' end with a 7-methylguanosine cap, which is a feature typical of eukaryotic mRNAs.
2. Recall that bacteria lack a nucleus, so their mRNA synthesis and translation occur in the cytoplasm simultaneously, unlike eukaryotes where mRNA is synthesized and processed in the nucleus before translation.
3. Recognize that bacterial mRNAs are often polycistronic, meaning a single mRNA molecule can encode multiple proteins. This is a key difference from most eukaryotic mRNAs, which are typically monocistronic (one mRNA, one protein).
4. Note that bacterial mRNAs usually have short poly(A) tails or none at all, and these tails often signal degradation rather than stabilization, which contrasts with the long poly(A) tails in eukaryotic mRNAs that help stabilize the transcript.
5. Based on these points, identify the statement that bacterial mRNAs are often polycistronic as the true statement among the options provided.