Related Experiment Video
Updated: Feb 6, 2026

In Vitro Assay to Measure Phosphatidylethanolamine Methyltransferase Activity
Published on: January 5, 2016
A bacterial methyltransferase M.EcoHK311 requires two proteins for in vitro methylation
Abstract:
The genes encoding EcoHK311 restriction-modification (R-M) system were isolated from a clinically-isolated Escherichia coli strain HK31. The entire R-M system of EcoHK311 is located in a 2.1 kb fragment. R.EcoHK311 is an isoschizomer of Eael which recognizes and cleaves Y decreases GGCCR. M.EcoHK31l consists of two polypeptides alpha and beta with sizes 309 and 176 aa, respectively. Polypeptide beta is encoded within aa, alternative reading frame of polypeptide alpha. All the conserved motifs in mC5-MTases can be found in polypeptide alpha except motif IX which is present in polypeptide beta. Polypeptides alpha and beta were separately synthesized in a T7 promoter controlled over-expression system and in vitro methylation occurred only when the two extracts were mixed and thus confirms that two polypeptides are required for methylation.
Related Concept Videos
Oxygen Requirements and Growth Patterns
Bacterial Translocation and Protein Secretion
Bacterial Protein Maturation
Proteins: Dietary Sources and Requirements
Requirements for Human Life
Oxygen
Atmospheric air is only about 20 percent oxygen, but that oxygen is a key component of the chemical reactions that keep the body alive, including the reactions that produce ATP. Brain cells are susceptible to a lack of oxygen because they require a...
Carbohydrates: Dietary Sources and Requirements

