ID   PHAE_SYNY3              Reviewed;         330 AA.
AC   P73389;
DT   15-FEB-2017, integrated into UniProtKB/Swiss-Prot.
DT   01-FEB-1997, sequence version 1.
DT   25-MAY-2022, entry version 94.
DE   RecName: Full=Poly(3-hydroxyalkanoate) polymerase subunit PhaE;
DE            Short=PHA polymerase;
DE   AltName: Full=PHB synthase subunit PhaE;
DE   AltName: Full=Poly(3-hydroxybutyrate) polymerase subunit PhaE;
DE            Short=PHB polymerase;
DE   AltName: Full=Poly(hydroxyalkanoic acid) synthase subunit PhaE;
DE            Short=PHA synthase {ECO:0000303|PubMed:9683655};
DE            Short=Polyhydroxyalkanoic acid synthase subunit PhaE {ECO:0000303|PubMed:9683655};
GN   Name=phaE {ECO:0000303|PubMed:9683655}; OrderedLocusNames=slr1829;
OS   Synechocystis sp. (strain PCC 6803 / Kazusa).
OC   Bacteria; Cyanobacteria; Synechococcales; Merismopediaceae; Synechocystis;
OC   unclassified Synechocystis.
OX   NCBI_TaxID=1111708;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC   STRAIN=PCC 6803 / Kazusa;
RX   PubMed=8905231; DOI=10.1093/dnares/3.3.109;
RA   Kaneko T., Sato S., Kotani H., Tanaka A., Asamizu E., Nakamura Y.,
RA   Miyajima N., Hirosawa M., Sugiura M., Sasamoto S., Kimura T., Hosouchi T.,
RA   Matsuno A., Muraki A., Nakazaki N., Naruo K., Okumura S., Shimpo S.,
RA   Takeuchi C., Wada T., Watanabe A., Yamada M., Yasuda M., Tabata S.;
RT   "Sequence analysis of the genome of the unicellular cyanobacterium
RT   Synechocystis sp. strain PCC6803. II. Sequence determination of the entire
RT   genome and assignment of potential protein-coding regions.";
RL   DNA Res. 3:109-136(1996).
RN   [2]
RP   GENE NAME.
RX   PubMed=1476773; DOI=10.1111/j.1574-6968.1992.tb05841.x;
RA   Steinbuechel A., Hustede E., Liebergesell M., Pieper U., Timm A.,
RA   Valentin H.;
RT   "Molecular basis for biosynthesis and accumulation of polyhydroxyalkanoic
RT   acids in bacteria.";
RL   FEMS Microbiol. Rev. 9:217-230(1992).
RN   [3]
RP   FUNCTION, PATHWAY, SUBUNIT, AND EXPRESSION IN E.COLI.
RC   STRAIN=ATCC 27184 / PCC 6803 / N-1;
RX   PubMed=9683655; DOI=10.1007/s002030050629;
RA   Hein S., Tran H., Steinbuechel A.;
RT   "Synechocystis sp. PCC6803 possesses a two-component polyhydroxyalkanoic
RT   acid synthase similar to that of anoxygenic purple sulfur bacteria.";
RL   Arch. Microbiol. 170:162-170(1998).
RN   [4]
RP   FUNCTION, BIOPHYSICOCHEMICAL PROPERTIES, AND SUBUNIT.
RC   STRAIN=ATCC 27184 / PCC 6803 / N-1;
RX   PubMed=25629766; DOI=10.1021/bi501560b;
RA   Numata K., Motoda Y., Watanabe S., Osanai T., Kigawa T.;
RT   "Co-expression of two polyhydroxyalkanoate synthase subunits from
RT   Synechocystis sp. PCC 6803 by cell-free synthesis and their specific
RT   activity for polymerization of 3-hydroxybutyryl-coenzyme A.";
RL   Biochemistry 54:1401-1407(2015).
CC   -!- FUNCTION: When expressed in E.coli with Synechocystis PhaC and
CC       C.necator PhaA and PhaB, confers the ability to synthesize up to 13%
CC       (w/w) poly(3-hydroxybutyrate) (PHB) depending on the carbon source; all
CC       4 genes are necessary for PHB production (PubMed:9683655). Cell-free in
CC       vitro coexpression with PhaE gives a heterodimer able to polymerize 3-
CC       hydroxybutyrate-CoA (PubMed:25629766). This subunit has no catalytic
CC       activity but enhances the activity of PhaC, the catalytic subunit (By
CC       similarity). {ECO:0000250|UniProtKB:P45372,
CC       ECO:0000269|PubMed:25629766, ECO:0000269|PubMed:9683655}.
CC   -!- BIOPHYSICOCHEMICAL PROPERTIES:
CC       Kinetic parameters:
CC         KM=478 uM for 3-hydroxybutyryl-CoA {ECO:0000269|PubMed:25629766};
CC   -!- PATHWAY: Biopolymer metabolism; poly-(R)-3-hydroxybutanoate
CC       biosynthesis. {ECO:0000305|PubMed:9683655}.
CC   -!- SUBUNIT: Forms a heterodimer with PhaC, which may multimerize in the
CC       presence of 3-hydroxybutyryl-CoA (PubMed:25629766). Both subunits are
CC       required for PHB synthesis in E.coli and in PHA-negative A.eutrophus.
CC       {ECO:0000269|PubMed:25629766, ECO:0000269|PubMed:9683655}.
CC   -!- SUBCELLULAR LOCATION: Cytoplasm {ECO:0000250|UniProtKB:P45372}.
CC   -!- BIOTECHNOLOGY: Poly(3-hydroxyalkanoic acids) (PHA), of which PHB is
CC       among the most common compounds, are prokaryotic intracellular storage
CC       compounds with potential uses as renewable, biodegradable
CC       thermoplastics. Cyanobacterial PHB synthesis is particularly attractive
CC       as cyanobacteria use CO(2) as the carbon source. {ECO:0000305}.
CC   -!- MISCELLANEOUS: Nitrogen-free medium induces chlorosis in Synechocystis,
CC       leading to the degradation of the photosynthetic apparatus and
CC       concomitant accumulation of cytoplasmic polyhydroxyalkanoic acid (PHA)
CC       granules which in this cyanobacterium are composed of PHB.
CC       {ECO:0000269|PubMed:9683655}.
CC   -!- SIMILARITY: Belongs to the PHA/PHB synthase family. Type III PhaE
CC       subfamily. {ECO:0000305}.
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DR   EMBL; BA000022; BAA17429.1; -; Genomic_DNA.
DR   PIR; S77326; S77326.
DR   AlphaFoldDB; P73389; -.
DR   SMR; P73389; -.
DR   STRING; 1148.1652508; -.
DR   PaxDb; P73389; -.
DR   EnsemblBacteria; BAA17429; BAA17429; BAA17429.
DR   KEGG; syn:slr1829; -.
DR   eggNOG; ENOG502ZA44; Bacteria.
DR   OMA; REENAPW; -.
DR   UniPathway; UPA00917; -.
DR   Proteomes; UP000001425; Chromosome.
DR   GO; GO:0005737; C:cytoplasm; IEA:UniProtKB-SubCell.
DR   GO; GO:0042619; P:poly-hydroxybutyrate biosynthetic process; IDA:UniProtKB.
DR   InterPro; IPR010123; PHA_synth_III_E.
DR   Pfam; PF09712; PHA_synth_III_E; 1.
DR   TIGRFAMs; TIGR01834; PHA_synth_III_E; 1.
PE   1: Evidence at protein level;
KW   Coiled coil; Cytoplasm; PHB biosynthesis; Reference proteome.
FT   CHAIN           1..330
FT                   /note="Poly(3-hydroxyalkanoate) polymerase subunit PhaE"
FT                   /id="PRO_0000438833"
FT   COILED          298..328
FT                   /evidence="ECO:0000255"
SQ   SEQUENCE   330 AA;  38047 MW;  675F688B3A910B22 CRC64;
     MESTNKTWTE LMTPLSQFWL ESSSQAWKNW FDLMAKGGAG AMMGSAPQSF ESLPQQFLQS
     QQFYGELLKL SFEAWQSLWP KLDNGSAPGA VQGYLKQLQT QIEQYTATTQ ALQGDMDGLW
     QCYIKEVQRF SQLWLSTWQS SVAPLGKLPT GDIHAWLDLN NLYGDALYNK NLSSFMRSPL
     LGPSREMNGK LLRAFDDWVK LSQAMADYQL LEADIQYRGF AALMEDLLAR AKEDKPVKTW
     KEFQQRWAIA ADQVFEEAFC EEKNLKVRGK FINALNRYRI QQQEILEAWL KMLNLPTRSE
     VDEIHQTIYQ LRKEVKSLKK RLGETEANPG