Protein: Serine/threonine-protein kinase StkP (Ser/Thr-protein kinase StkP) (EC 2.7.11.1) (Eukaryotic-type Ser/Thr protein kinase) (ESTPK) (Q8KY50)
Organism: Streptococcus pneumoniae
Function: Protein kinase involved in signal transduction pathways that regulate various cellular processes. Likely senses intracellular peptidoglycan subunits present in the cell division septa of actively growing cells; thus, intracellular unlinked peptidoglycan may serve as the signal molecules that trigger StkP phosphorylation activity on a set of substrates. Plays a crucial role in the regulation of cell shape and cell division of S.pneumoniae through control of at least DivIVA activity. Is involved in competence triggering, via the transduction of signals culminating directly or indirectly in ComD activation. Is important for the resistance of S.pneumoniae to various environmental stress conditions. Appears to be a global regulator that positively controls the transcription of a set of genes encoding functions involved in cell wall metabolism, pyrimidine biosynthesis, DNA repair, iron uptake, and oxidative stress response, and that seems to down-regulate genes employed in competence. Since StkP is unlikely to directly regulate transcription, the input signal must be transmitted through an effector molecule. Identified target substrates that are specifically phosphorylated by StkP in vivo, mainly on threonine residues, are DivIVA, GlmM, PpaC, MapZ, KhpB (also called EloR/Jag) and StkP itself. Autophosphorylated StkP is a substrate for the cotranscribed protein phosphatase PhpP; PhpP and StkP appear to constitute a functional signaling couple in vivo.
Subcellular location: Cell membrane {ECO:0000269|PubMed:15720398, ECO:0000269|PubMed:17307148, ECO:0000269|PubMed:19502404, ECO:0000269|PubMed:22431591}; Single-pass membrane protein {ECO:0000269|PubMed:15720398, ECO:0000269|PubMed:17307148, ECO:0000269|PubMed:19502404, ECO:0000269|PubMed:22431591}. Note=The C-terminal PASTA domain is located in the periplasmic space, beneath the peptidoglycan cell wall, and the kinase domain is located in the cytoplasm. However, another study in the virulent strain TIGR4 (PubMed:20223804) showed that the C-terminal PASTA domain is exposed extracellularly. Localizes to the midcell division sites.
Sequence: MIQIGKIFAGRYRIVKQIGRGGMADVYLAKDLILDGEEVAVKVLRTNYQTDPIAVARFQREARAMADLDHPHIVRITDIGEEDGQQYLAMEYVAGLDLKRYIKEHYPLSNEEAVRIMRQILLAMRLAHTRGIVHRDLKPQNILLTPDGTAKVTDFGIAVAFAETSLTQTNSMLGSVHYLSPEQARGSKATVQSDIYAMGIIFYEMLTGHIPYDGDSAVTIALQHFQNPLPSVIAENSSVPQALENVIIKATAKKLTNRYRSVSEMYVDLSSSLSYNRRNESKLIFDETSKADTKTLPKVSQSTLTSIPKVQAQTEHKSIKNPSQAVTEETYQPQAPKKHRFKMRYLILLASLVLVAASLIWILSRSPATIAIPDVAGQTVAEAKATLKKANFEIGEEKTEASEKVEEGRIIRTDPGAGTGRKEGTKINLVVSSGKQSFQISNYVGRKSSDVIAELKEKKVPDNLIKIEEEESNESEAGTVLKQSLPEGTTYDLSKATQIVLTVAKKATTIQLGNYIGRNSTEVISELKQKKVPENLIKIEEEESSESEPGTIMKQSPGAGTTYDVSKPTQIVLTVAKKVTSVAMPSYIGSSLEFTKNNLIQIVGIKEANIEVVEVTTAPAGSVEGMVVEQSPRAGEKVDLNKTRVKISIYKPKTTSATP
InterPro domains: - IPR011009: Protein kinase-like domain superfamily (homologous_superfamily) [8-285]
- IPR008271: Serine/threonine-protein kinase, active site (active_site) [132-144]
- IPR017441: Protein kinase, ATP binding site (binding_site) [18-42]
- IPR000719: Protein kinase domain (domain) [12-273]
- IPR005543: PASTA domain (domain) [366-651]
Gene Ontology annotations:
Molecular Function (MF): GO:0003674 (molecular function), GO:0003824 (catalytic activity), GO:0016740 (transferase activity), GO:0140096 (catalytic activity, acting on a protein), GO:0004672 (protein kinase activity), GO:0016772 (transferase activity, transferring phosphorus-containing groups), GO:0016773 (phosphotransferase activity, alcohol group as acceptor), GO:0004674 (protein serine/threonine kinase activity), GO:0016301 (kinase activity)
Biological Process (BP): GO:0008150 (biological process), GO:0008152 (metabolic process), GO:0065007 (biological regulation), GO:0050896 (response to stimulus), GO:0050789 (regulation of biological process), GO:0044419 (biological process involved in interspecies interaction between organisms), GO:0032502 (developmental process), GO:0009987 (cellular process), GO:0023052 (signaling), GO:0009605 (response to external stimulus), GO:0048869 (cellular developmental process), GO:0044237 (cellular metabolic process), GO:0042221 (response to chemical), GO:0009607 (response to biotic stimulus), GO:0009719 (response to endogenous stimulus), GO:0006807 (nitrogen compound metabolic process), GO:0050794 (regulation of cellular process), GO:0051716 (cellular response to stimulus), GO:0071704 (organic substance metabolic process), GO:0051707 (response to other organism), GO:0007154 (cell communication), GO:0007165 (signal transduction), GO:0044238 (primary metabolic process), GO:1901564 (organonitrogen compound metabolic process), GO:0043207 (response to external biotic stimulus), GO:0009847 (spore germination), GO:1901698 (response to nitrogen compound), GO:0070887 (cellular response to chemical stimulus), GO:0009617 (response to bacterium), GO:0019538 (protein metabolic process), GO:0071495 (cellular response to endogenous stimulus), GO:1901700 (response to oxygen-containing compound), GO:0043170 (macromolecule metabolic process), GO:0071216 (cellular response to biotic stimulus), GO:0010033 (response to organic substance), GO:0006793 (phosphorus metabolic process), GO:0036211 (protein modification process), GO:0071417 (cellular response to organonitrogen compound), GO:0071219 (cellular response to molecule of bacterial origin), GO:0043412 (macromolecule modification), GO:0010243 (response to organonitrogen compound), GO:0071310 (cellular response to organic substance), GO:0032494 (response to peptidoglycan), GO:1901699 (cellular response to nitrogen compound), GO:0002237 (response to molecule of bacterial origin), GO:0006796 (phosphate-containing compound metabolic process), GO:1901701 (cellular response to oxygen-containing compound), GO:0006468 (protein phosphorylation), GO:0016310 (phosphorylation)
Cellular Component (CC): GO:0005575 (cellular component), GO:0110165 (cellular anatomical entity), GO:0071944 (cell periphery), GO:0030312 (external encapsulating structure), GO:0005618 (cell wall), GO:0009274 (peptidoglycan-based cell wall)