Spinal muscular atrophy (SMA) is an inherited disease in which spinal cord neurones die for no known reason. The disease is inevitably fatal in childhood due to an inability to breathe or swallow. Michael Sattler and colleagues from the European Molecular Biology Laboratory in Heidelberg, Germany points out that the neurones' death may be caused only by a change in the binding structure of "survival of motor neurone" (SMN) protein (
Researchers identified the three-dimensional structure of the so-called "Tudor domain" in the SMN protein and showed that a gene mutation, characteristic for SMA, affects only the charge distribution of the domain binding site and not the whole protein shape. This may explain the lack of SMN interaction with partner proteins, called Sm, that are fundamental components for the task of RNA splicing and neurone survival.