Before revision:  To implement this multi-family EC analysisstrategy, this paper presents a novel joint graphical lasso method to model a set of related protein families . In particular, we model a set of related families using a set of correlated multivariate Gaussian distributions, the inverse covariance matrix (or precision matrix) of each distribution encoding the contact pattern of one family. Then we co-estimate the precision matrices by maximizing the occurring probability of all the involved sequences , subject to the constraint that the  matrices shall share similar patterns .
After revision:  To implement this multi-family EC analysisstrategy, this paper presents a novel joint graphical lasso method to model a set of related protein families using Gaussian graphical models (GGM) and then co-estimate the precision matrices by maximizing the occurring probability of all the involved sequences , subject to the constraint that the matrices shall share similar patterns .