ISSN 10214437, Russian Journal of Plant Physiology, 2013, Vol. 60, No. 4, pp. 511–517. © Pleiades Publishing, Ltd., 2013.
Original Russian Text © E.S. Pojidaeva, S. Malterer, A.S. Baik, A.V. Sokolenko, 2013, published in Fiziologiya Rastenii, 2013, Vol. 60, No. 4, pp. 541–548.
Many proteins undergo proteolysis by acting of
proline peptidases [1–3]. This group of enzymes carry
out selective proteolysis of proteins , hydrolyzing
the peptide bonds formed by proline. This activity is
determined by the molecule isomeric state (
and proline position in it . There are prolinespe
cific metallopeptidases (aminopeptidase P, carboxy
peptidase P, and prolidase), which activities depend on
bivalent metals, and also serinetype proline pepti
dases (prolyloligopeptidases, dipeptidylpeptidases II
and IV, and prolylcarboxypeptidase), with SerAsp
His triade in the catalytic center [3, 6, 7].
To date, the proline aminopeptidase PII of the het
AMPPII) is well characterized . In the database
MEROPS, AMPPII is classified to the subfamily of
M24B peptidases , which remove the Nterminal
amino acid residue of proteins and peptides only in the
case of a penultimate proline position . The high
est in vitro activity of
AMPPII was observed in
the presence of Mn
. This enzyme has significant
structural similarity to other aminopeptidases , for
example, methionine aminopeptidases removing the
Nterminal methionine during protein translation
 and also XaaPro dipeptidases and prolidases.
Inactivation of genes encoding methionine ami
nopeptidases is lethal for most organisms, which indi
cates their vitally important function in the cells.
The proteolysis of Nterminal amino acid residues
of polypeptides is characteristic of all living organisms
and is well studied in heterotrophic prokaryotes and
eukaryotes, but not in photosynthetic organisms.
According to the CyanoBase database (http://genome.
), the genome of
the unicellular cyanobacterium
) encodes 25 various aminopepti
dases [12, 13]. The function of proline aminopepti
is not studied until now. Earlier,
we have inactivated the
gene encoding putative
proline aminopeptidase PepP of
directed mutagenesis. The
mutant was capable
for photoautotrophic growth; however, it grew slower
than the wildtype strain . In this work the physio
logical and biochemical analyses of the
were performed to investigate the function of PepP
. We also analyzed the kinetics
of protein accumulation for basic photosynthetic
complexes under standard growth conditions in the
mutant to compare with the wild type.
MATERIALS AND METHODS
Strains and culturing conditions.
was obtained from the collec
tion of the Department of Genetics, Moscow State
sp. PCC 6803 Results
in the Disturbance in Protein Biogenesis of Photosynthetic
E. S. Pojidaeva
, S. Malterer
, A. S. Baik
, and A. V. Sokolenko
Department of Biology I, Ludwig Maximilian University, Munich, Germany
Timiryazev Institute of Plant Physiology, Russian Academy of Sciences, Botanicheskaya ul. 35, Moscow, 127276 Russia;
fax: 8 (499) 9778018; email: firstname.lastname@example.org
Received October 29, 2012
—The genome of cyanobacterium
sp. PCC 6803 contains the
encoding the putative homolog of proline aminopeptidase PII (AMPPII) of the heterotrophic bacterium
AMPPII is known to cleave the Nterminal amino acid residue of peptides and proteins only
in the case of a penultimate proline position. The
sp. PCC 6803 insertion mutant with inacti
gene is characterized by the reduced content of phycobiliproteins and also proteins of photosystem
II, which may be related to the reduced synthesis or stability of corresponding proteins. A possible involve
ment of PepP in biogenesis of proteins of the photosynthetic apparatus is discussed.
sp. PCC 6803, aminopeptidase, protein synthesis
: AMPP—aminopeptidase P; APC—allophycocya
nin; CPC—phycocyanin; PepP—proline aminopeptidase P;
PS—photosystem; SI—standard illumination;
sp. PCC 6803.