(It's "deux".)

but I don't know how to get the same series of bases in the substitution. 

s/([actg]{6})/...$1.../

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Also I need to capture the locus name and place it before the ^^

You should have gotten a warning saying you were matching against an undefined value. 
my ($locus) = /LOCUS\s*(\w+)/;

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In reply to Re: Writing to file part deux by ikegami
in thread Writing to file part duex by perl_n00b

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