In dimeric filaments of MSA, K58 of protofilament B makes a salt bridge with E35 of protofilament A. There is a second salt bridge between K60 of protofilament B and E28 of protofilament A. In our model of JOS filaments that are only made of mutant α-synuclein, there are equivalent salt bridges between K65 and E20, and between K67 and E13, which stabilise the interaction between the filament core and the N-terminal region. This evidence concerns the gene SNCA and multiple system atrophy.