MinZscore is used in LAMA search. 
For more details about LAMA algorithm go to LAMA link or directly to the LAMA help
MinZscore is a minimal Zscore value required for an edge to be added to cyrca sets. 
For more details about CYRCA see Kunin et al, "Consistency Analysis of Similarity 
between Multiple Alignments: Prediction of Protein Function and Fold Structure
from Analysis of Local Sequence Motifs", 2001,vol.307,939-949.