PMC:2724173 / 10828-11916 JSONTXT

{"project":"2_test","denotations":[{"id":"18304577-8377180-62526552","span":{"begin":54,"end":56},"obj":"8377180"},{"id":"18304577-15572779-62526553","span":{"begin":115,"end":117},"obj":"15572779"},{"id":"18304577-12894216-62526554","span":{"begin":488,"end":490},"obj":"12894216"},{"id":"18304577-17060447-62526555","span":{"begin":637,"end":639},"obj":"17060447"},{"id":"18304577-16086183-62526556","span":{"begin":870,"end":872},"obj":"16086183"},{"id":"18304577-17485524-62526556","span":{"begin":870,"end":872},"obj":"17485524"},{"id":"18304577-11115111-62526557","span":{"begin":1087,"end":1088},"obj":"11115111"}],"text":"A structural homology search using the DALI algorithm,24 and the Secondary Structure Matching algorithm of MSDfold,25 was unable to identify any protein, other than YopN, possessing multiple X-bundle motifs. However, two classes of proteins were identified that possess X-bundle motifs similar to the individual domains of MxiC. The structural homologues belonged to the Bcl-2 family of apoptosis regulators, specifically the Caenorhabditis elegans homologue Ced9 (DALI Z-score 4.3, 1ohu)26 and the programmed cell death proteins involved in inhibition of protein synthesis, specifically the MA3 domain of Pdcd4 (DALI Z-score 3.9, 2nsz).27 Although the significance of these similarities is uncertain, structural mimicry of apoptotic factors is a common theme seen in viral and bacterial pathogens and represents an important defense against the host immune response.28,29 This structural similarity may be of functional relevance, as MxiC has been identified as a protein that is secreted by the T3SS under conditions that mimic those encountered by bacteria during infection of a host.3"}