The invention also relates to DNA constructs encoding the variants, and to {HEAD ~ vectors} and cells harboring {TAIL ~ the DNA constructs} 
harboring
The invention also relates to DNA constructs encoding the variants , and to { HEAD ~ vectors } and cells harboring { TAIL ~ the DNA constructs }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD OTH OTH REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL