MATLAB: Split string into 3 letter each

Question

if have a

 str = 'AGTCTGTCTTTG';

i wanted to split it into 3 letters each

 AGT        CTG        TCT      TTG

and replace

 AGT with J
 CTG with U
 TCT with N
 TTG with D

how to do it… please do reply….

i did as below

 str = 'AGTCTGTCTTTG';
 j = 1;
 for k = 1: 3: length(str)
   word(j) = str(k : k +3)
   j = j+1;
 end

but i get error as

 ??? Subscripted assignment dimension mismatch.
Error in ==> Untitled2 at 4
word(j) = str(k : k +3)

please do reply….

Answer 1

str ='AGTCTGTCTTTG';
a=cellstr(reshape(str,3,[])')

What is the aim of the replacement ? you can create

v={'J','U','N','D'}