What is the source of a matrix ending up with “_B” like “V$MYCMAX_B”?
These matrices (like those ending in “_C”) were obtained from our colleagues at the GSF in Munich. Some of them were constructed by these colleagues, while others where taken from the cited references. In the matrix table of TRANSFAC®, some of the entries have a list of binding sites that the weight matrix was built from but some do not. In most of these cases only the matrix, but not the sites, were published. In such cases we usually try to contact the authors to get the sites as well, but in some instances we did not get a response. In other cases the matrices were constructed at a time when the structure of the database did not allow for storing the links between matrix and sites.
