the mt-dna is traced through maternal lineages, and it is indeed a little bit curious to find it in north america. this is not because it clusters specifically with jews - in fact, it does not. it actually clusters with greeks. search terms would be "mt-dna haplotype X". the wiki map is good at showing where it clusters.
it clusters as a minority lineage everywhere it exists, so it is very difficult to try and determine it's origin using migration patterns. molecular testing has suggested that the lineage probably originated in central asia and migrated over to the americas with the bering land bridge, while it also stayed behind in asia and floated towards greece. but, molecular testing of this sort is a kind of house of cards argument.
a more interesting - and probably more correct - suggestion is the idea that it may be a carthaginian lineage. this would suggest pre-columbian transoceanic contact - which is an idea that is increasingly gaining momentum. we can measure the effect of colonialism in the native american gene pool (you may have noticed that many people that identify as natives actually look very white; in fact, some tribes report upwards of 90% european dna on the male side). it's entirely reasonable to suggest that carthaginian contact may have left some evidence of itself.
but, this is not the dominant theory. the dominant theory is that X developed in the steppes and found it's way into the greek speaking areas by genetic drift, then spread around those areas through trade.