Subcellular localization of DNA ligase III-GFP fusion proteins. (A) DNA ligase III-GFP fusion constructs. White boxes, GFP coding region; hatched boxes, DNA ligase III cDNA nucleotides 73 to 333; shaded boxes, ATG codons; arrowheads; cytomegalovirus promoter; thin lines, vector sequences. Construction of vectors is described in Materials and Methods. (B) Subcellular localization of DNA ligase III-GFP fusion proteins. Cos-1 cells were transiently transfected with GFP plasmid constructs pEGFP-N1 (a), pLIG3-GFP-1 (b), pLIG3-GFP-2 (c), and pLIG3-GFP-3 (d) and observed under a Bio-Rad confocal microscope 24 h following transfection.