We’d like to make a minor edit to our protocol, “Site-specific Incorporation of Phosphoserine into Recombinant Proteins in Escherichia coli”, 10.21769/BioProtoc.4541.

In the Materials and Reagents Section, in Expression strain options we list:

1. B95(DE3) ∆A ∆fabR ∆serB (Zhu et al., 2019). Available upon request.
   

We now have this strain publicly available on Addgene.

It should be changed to:

1. B95(DE3) ∆A ∆fabR ∆serB (Zhu et al., 2019). Available from Addgene #197655.