Structure of the catalytic domain of a state transition kinase homolog from Micromonas algae
Protein & Cell
;
(12): 607-619, 2013.
Artigo
em Inglês
| WPRIM
| ID: wpr-757782
ABSTRACT
Under natural environments, plants and algae have evolved various photosynthetic acclimation mechanisms in response to the constantly changing light conditions. The state transition and long-term response processes in photosynthetic acclimation involve remodeling and composition alteration of thylakoid membrane. A chloroplast protein kinase named Stt7/STN7 has been found to have pivotal roles in both state transition and long-term response. Here we report the crystal structures of the kinase domain of a putative Stt7/STN7 homolog from Micromonas sp. RCC299 (MsStt7d) in the apo form and in complex with various nucleotide substrates. MsStt7d adopts a canonical protein kinase fold and contains all the essential residues at the active site. A novel hairpin motif, found to be a conserved feature of the Stt7/STN7 family and indispensable for the kinase stability, interacts with the activation loop and fixes it in an active conformation. We have also demonstrated that MsStt7d is a dualspecifi city kinase that phosphorylates both Thr and Tyr residues. Moreover, preliminary in vitro data suggest that it might be capable of phosphorylating a consensus N-terminal pentapeptide of light-harvesting proteins Micromonas Lhcp4 and Arabidopsis Lhcb1 directly. The potential peptide/protein substrate binding site is predicted based on the location of a pseudo-substrate contributed by the adjacent molecule within the crystallographic dimer. The structural and biochemical data presented here provide a framework for an improved understanding on the role of Stt7/STN7 in photosynthetic acclimation.
Texto completo:
DisponíveL
Índice:
WPRIM (Pacífico Ocidental)
Assunto principal:
Fosforilação
/
Especificidade por Substrato
/
Sítios de Ligação
/
Dados de Sequência Molecular
/
Química
/
Alinhamento de Sequência
/
Sequência de Aminoácidos
/
Proteínas Serina-Treonina Quinases
/
Estrutura Secundária de Proteína
/
Arabidopsis
Idioma:
Inglês
Revista:
Protein & Cell
Ano de publicação:
2013
Tipo de documento:
Artigo
Similares
MEDLINE
...
LILACS
LIS