How to download sequence of a protein from all available species from NCBI?

Question

[arijitghosh2009]

I want to download sequences from all available species in NCBI protein database for one particular protein. Any available methods in R? It takes a long time doing it manually.

[GenoMax]

Not R but you can use EntrezDirect:

esearch -db protein -query "dnaK" | efetch -format fasta > protein.fa

[Joseph Hughes]

You can use the package Rentrez in R with a similar syntax to what @GenoMax suggested.