PSBU_CYACA
ID PSBU_CYACA Reviewed; 154 AA.
AC Q9ZQS5; Q9T2H0;
DT 01-JUN-2001, integrated into UniProtKB/Swiss-Prot.
DT 01-JUN-2001, sequence version 2.
DT 25-MAY-2022, entry version 71.
DE RecName: Full=Photosystem II 12 kDa extrinsic protein, chloroplastic {ECO:0000305|PubMed:8534673};
DE AltName: Full=PS II complex 12 kDa extrinsic protein {ECO:0000303|PubMed:10381374};
DE AltName: Full=PSII-U;
DE Flags: Precursor;
GN Name=psbU {ECO:0000303|PubMed:10381374};
OS Cyanidium caldarium (Red alga).
OC Eukaryota; Rhodophyta; Bangiophyceae; Cyanidiales; Cyanidiaceae; Cyanidium.
OX NCBI_TaxID=2771;
RN [1]
RP NUCLEOTIDE SEQUENCE [MRNA].
RX PubMed=10381374; DOI=10.1006/bbrc.1999.0763;
RA Ohta H., Okumura A., Okuyama S., Akiyama A., Iwai M., Yoshihara S.,
RA Shen J.-R., Kamo M., Enami I.;
RT "Cloning, expression of the psbU gene, and functional studies of the
RT recombinant 12-kDa protein of photosystem II from a red alga Cyanidium
RT caldarium.";
RL Biochem. Biophys. Res. Commun. 260:245-250(1999).
RN [2]
RP PROTEIN SEQUENCE OF 62-112, AND SUBCELLULAR LOCATION.
RC STRAIN=Geitler;
RX PubMed=8534673; DOI=10.1016/0005-2728(95)00122-0;
RA Enami I., Murayama H., Ohta H., Kamo M., Nakazato K., Shen J.-R.;
RT "Isolation and characterization of a Photosystem II complex from the red
RT alga Cyanidium caldarium: association of cytochrome c-550 and a 12 kDa
RT protein with the complex.";
RL Biochim. Biophys. Acta 1232:208-216(1995).
RN [3]
RP SUBUNIT, AND RECONSTITUTION EXPERIMENTS.
RC STRAIN=RK-1;
RX PubMed=12941874; DOI=10.1093/pcp/pcg106;
RA Enami I., Iwai M., Akiyama A., Suzuki T., Okumura A., Katoh T., Tada O.,
RA Ohta H., Shen J.-R.;
RT "Comparison of binding and functional properties of two extrinsic
RT components, cyt c550 and a 12 kDa protein, in cyanobacterial PSII with
RT those in red algal PSII.";
RL Plant Cell Physiol. 44:820-827(2003).
CC -!- FUNCTION: Stabilizes the structure of photosystem II oxygen-evolving
CC complex (OEC), the ion environment of oxygen evolution and protects the
CC OEC against heat-induced inactivation (By similarity). Does not bind by
CC itself to PSII; it requires all other members of the OEC.
CC {ECO:0000250}.
CC -!- SUBUNIT: The oxygen-evolving complex in red algae is composed of PsbO
CC (OEC33), PsbQ', cytochrome c-550 and PsbU.
CC {ECO:0000269|PubMed:12941874}.
CC -!- SUBCELLULAR LOCATION: Plastid, chloroplast thylakoid membrane
CC {ECO:0000269|PubMed:8534673}; Peripheral membrane protein
CC {ECO:0000269|PubMed:8534673}; Lumenal side
CC {ECO:0000269|PubMed:8534673}. Note=Associated with photosystem II at
CC the lumenal side of the thylakoid membrane.
CC {ECO:0000269|PubMed:8534673}.
CC -!- PTM: Predicted to be translocated into the thylakoid lumen by the Tat
CC system. The position of the first transit peptide cleavage has not been
CC experimentally proven. {ECO:0000305}.
CC -!- SIMILARITY: Belongs to the PsbU family. {ECO:0000305}.
CC -!- SEQUENCE CAUTION:
CC Sequence=BAA75398.1; Type=Erroneous initiation; Evidence={ECO:0000305};
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DR EMBL; AB023805; BAA75398.1; ALT_INIT; mRNA.
DR PDB; 4YUU; X-ray; 2.77 A; U1/U2/u1/u2=1-154.
DR PDBsum; 4YUU; -.
DR AlphaFoldDB; Q9ZQS5; -.
DR SMR; Q9ZQS5; -.
DR GO; GO:0009535; C:chloroplast thylakoid membrane; IEA:UniProtKB-SubCell.
DR GO; GO:0019898; C:extrinsic component of membrane; IEA:InterPro.
DR GO; GO:0009654; C:photosystem II oxygen evolving complex; IEA:InterPro.
DR GO; GO:0015979; P:photosynthesis; IEA:UniProtKB-KW.
DR GO; GO:0042549; P:photosystem II stabilization; IEA:InterPro.
DR InterPro; IPR010527; PSII_PsbU.
DR InterPro; IPR006311; TAT_signal.
DR Pfam; PF06514; PsbU; 1.
DR PROSITE; PS51318; TAT; 1.
PE 1: Evidence at protein level;
KW 3D-structure; Chloroplast; Direct protein sequencing; Electron transport;
KW Membrane; Photosynthesis; Photosystem II; Plastid; Thylakoid;
KW Transit peptide; Transport.
FT TRANSIT 1..36
FT /note="Chloroplast"
FT /evidence="ECO:0000255"
FT TRANSIT 37..61
FT /note="Thylakoid"
FT /evidence="ECO:0000269|PubMed:8534673"
FT CHAIN 62..154
FT /note="Photosystem II 12 kDa extrinsic protein,
FT chloroplastic"
FT /id="PRO_0000029609"
FT CONFLICT 80
FT /note="N -> D (in Ref. 2; AA sequence)"
FT /evidence="ECO:0000305"
FT CONFLICT 90
FT /note="F -> I (in Ref. 2; AA sequence)"
FT /evidence="ECO:0000305"
SQ SEQUENCE 154 AA; 16715 MW; EF28D01ABEC0977F CRC64;
MAFISTPLGK VTVKSATVSA NRRGLRMQSD SEPVVSRRAL LSGALAAAVA AALARARPAQ
ARIDYEGIGY LGGGDKIDVN NANVRAYRKF PGLYPTAAKK IVQGGPYGTP DDILKNPELS
ERDKEVIKKY MDRFVALPPT PEYFTDRVNN GIYK
