Conservation of the regulated structure of folded myosin 2 in species separated by at least 600 million years of independent evolution

@article{citeulike:2763966, abstract = {The myosin 2 family of molecular motors includes isoforms regulated in different ways. Vertebrate smooth-muscle myosin is activated by phosphorylation of the regulatory light chain, whereas scallop striated adductor-muscle myosin is activated by direct calcium binding to its essential light chain. The paired heads of inhibited molecules from myosins regulated by phosphorylation have an asymmetric arrangement with motor-motor interactions. It was unknown whether such interactions were a common motif for inactivation used in other forms of myosin-linked regulation. Using electron microscopy and single-particle image processing, we show that indistinguishable structures are indeed found in myosins and heavy meromyosins isolated from scallop striated adductor muscle and turkey gizzard smooth muscle. The similarities extend beyond the shapes of the heads and interactions between them: In both myosins, the tail folds into three segments, apparently at identical sites; all three segments are in close association outside the head region; and two segments are associated in the same way with one head in the asymmetric arrangement. Thus, these organisms, which have different regulatory mechanisms and diverged from a common ancestor >600 Myr ago, have the same quaternary structure. Conservation across such a large evolutionary distance suggests that this conformation is of fundamental functional importance. 10.1073/pnas.0707846105}, author = {Jung, Hyun S. and Burgess, Stan A. and Billington, Neil and Colegrave, Melanie and Patel, Hitesh and Chalovich, Joseph M. and Chantler, Peter D. and Knight, Peter J. }, citeulike-article-id = {2763966}, doi = {10.1073/pnas.0707846105}, journal = {Proceedings of the National Academy of Sciences}, keywords = {clip, em, myosin, structure}, month = {April}, number = {16}, pages = {6022--6026}, posted-at = {2008-05-07 07:29:50}, priority = {2}, title = {Conservation of the regulated structure of folded myosin 2 in species separated by at least 600 million years of independent evolution}, url = {http://dx.doi.org/10.1073/pnas.0707846105}, volume = {105}, year = {2008} }

TY - JOUR ID - citeulike:2763966 L3 - citeulike-article-id:2763966 TI - Conservation of the regulated structure of folded myosin 2 in species separated by at least 600 million years of independent evolution JF - Proceedings of the National Academy of Sciences VL - 105 IS - 16 SP - 6022 EP - 6026 N2 - The myosin 2 family of molecular motors includes isoforms regulated in different ways. Vertebrate smooth-muscle myosin is activated by phosphorylation of the regulatory light chain, whereas scallop striated adductor-muscle myosin is activated by direct calcium binding to its essential light chain. The paired heads of inhibited molecules from myosins regulated by phosphorylation have an asymmetric arrangement with motor-motor interactions. It was unknown whether such interactions were a common motif for inactivation used in other forms of myosin-linked regulation. Using electron microscopy and single-particle image processing, we show that indistinguishable structures are indeed found in myosins and heavy meromyosins isolated from scallop striated adductor muscle and turkey gizzard smooth muscle. The similarities extend beyond the shapes of the heads and interactions between them: In both myosins, the tail folds into three segments, apparently at identical sites; all three segments are in close association outside the head region; and two segments are associated in the same way with one head in the asymmetric arrangement. Thus, these organisms, which have different regulatory mechanisms and diverged from a common ancestor >600 Myr ago, have the same quaternary structure. Conservation across such a large evolutionary distance suggests that this conformation is of fundamental functional importance. 10.1073/pnas.0707846105 KW - clip KW - em KW - myosin KW - structure AU - Jung, Hyun AU - Burgess, Stan AU - Billington, Neil AU - Colegrave, Melanie AU - Patel, Hitesh AU - Chalovich, Joseph AU - Chantler, Peter AU - Knight, Peter PY - 2008/04/22/ UR - http://dx.doi.org/10.1073/pnas.0707846105 ER -