The major light-harvesting complex (LHCII) of photosystem I1 can be reconstituted in its native, trimeric form starting from its apoprotein light-harvesting chlorophyll alb-binding protein (LHCP), pigments, and thylakoid lipids. In this paper we identify segments in the LHCP polypeptide that are essential for the formation of stable LHCII trimers by analyzing N-and C-terminal deletion mutants of LHCP and mutants carrying point-specific amino acid exchanges. C-Terminal deletions that do not abolish pigment binding to LHCP do not affect trimerization either. By contrast, on the N-terminus of LHCP, where as many as 61 amino acids can be deleted without significant effects on pigment binding, only 15 amino acids are dispensible for LHCII trimer formation . This indicates that structural elements between amino acids 16 and 61 are involved in the stabilization of LHCII trimers but not monomers. Closer inspection of this protein domain in a more detailed mutation analysis revealed that amino acids W16 and/or Y17 as well as R21 are essential for the formation of LHCII trimers. These amino acids are conserved in virtually all known sequences of LHCII apoproteins but only in some of the minor chlorophyll alb complexes. Possible functions of the crucial residues are discussed.In the photosynthetic apparatus in higher plants, both photosystem I and photosystem I1 (PSI and PSII, respectively)' contain a number of peripheral, chlorophyll aib-
Wenn sich in Italien jemand mit Präzision auskennt, dann ist es die Firma MG Marposs. Um die Qualität der im Kundenauftrag gefertigten Messmittel und Master-Bauteile zu sichern, vertraut das Unternehmen am Standort Brescia seit mittlerweile sechs Jahren auf die Messtechnik-Expertise von Zeiss. Aufgrund der durchweg positiven Erfahrungen mit den Koordinatenmessgeräten, der Software „Calypso“ und dem dazugehörigen Service hat sich die Marposs-Gruppe entschieden, weitere Messmaschinen der Oberkochener in verschiedenen Fertigungsstätten einzusetzen.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.