Difference between revisions of "Part:BBa K1080008"

Revision as of 00:57, 16 October 2014

ChlP

Geranylgeranyl reductase - ChlP encodes a hydrogenase enzyme which catalyses the terminal hydrogenation steps of bacteriochlorophyll biosynthesis [1]. The enzyme, called geranylgeranyl reductase (ChlP or GGR) is responsible for catalysing the hydrogenation of geranylgeranyl diphosphate (GGPP), reducing its’ double bonds to form phytol pyrophosphate, which is required for the synthesis of chlorophylls, carotenoids, quinones and tocopherols [1-3].
Tanaka, et al. [3] showed that by mutating the ChlP gene in transgenic tobacco plants, reducing its activity, both chlorophyll and tocopherol levels are lowered. The transgenic plants had a slower growth rate and a gradually reduced chlorophyll content. They also showed low pigmentation in comparison to the controls.

Usage and Biology

Figure 1: (A)Italic text Structures of chlorophyllide a and bacteriochlorophyllide a. (B)Italic text The terminal hydrogenation steps of (bacterio)chlorophyll synthesis, showing gradual reduction of the geranylgeranyl double bonds. R could be either chlorophyllide, bacteriochlorophyllide, or a diphosphate group. [1]

Sequence and Features

Amino acid sequence

MVIGGGPSGA CAAETLAKGG VETFLLERKL DNCKPCGGAI PLCMVEEFDL PMEIIDRRVT
KMKMISPSNR EVDVGKTLSE TEWIGMCRRE VFDDYLRNRA QKLGANIVNG LFMRSEQQSA
EGPFTIHYNS YEDGSKMGKP ATLEVDMIIG ADGANSRIAK EIDAGEYDYA IAFQERIRIP
DDKMKYYENL AEMYVGDDVS PDFYGWVFPK YDHVAVGTGT VVNKTAIKQY QQATRDRSKV
KTEGGKIIRV EAHPIPEHPR PRRCKGRVAL VGDAAGYVTK CSGEGIYFAA KSGRMAAEAI
VEGSANGTKM CGEDAIRVYL DKWDRKYWTT YKVLDILQKV FYRSNPAREA FVELCEDSYV
QKMTFDSYLY KTVVPGNPLD DVKLLVRTVS SILRSNALRS VNSKSVNVSF GSKANEERVM
AA

References and documentation are available. Please note the modified algorithm for extinction coefficient.

Number of amino acids: 422

Molecular weight: 47011.7

Theoretical pI: 7.48

Amino acid composition:
Ala (A) 36 8.5%
Arg (R) 28 6.6%
Asn (N) 16 3.8%
Asp (D) 27 6.4%
Cys (C) 9 2.1%
Gln (Q) 9 2.1%
Glu (E) 31 7.3%
Gly (G) 35 8.3%
His (H) 4 0.9%
Ile (I) 24 5.7%
Leu (L) 23 5.5%
Lys (K) 31 7.3%
Met (M) 15 3.6%
Phe (F) 13 3.1%
Pro (P) 17 4.0%
Ser (S) 25 5.9%
Thr (T) 19 4.5%
Trp (W) 4 0.9%
Tyr (Y) 20 4.7%
Val (V) 36 8.5%
Pyl (O) 0 0.0%
Sec (U) 0 0.0%

(B)   0	  0.0%
(Z)   0	  0.0%
(X)   0	  0.0%

Total number of negatively charged residues (Asp + Glu): 58 Total number of positively charged residues (Arg + Lys): 59

Atomic composition:

Carbon C 2069 Hydrogen H 3278 Nitrogen N 574 Oxygen O 628 Sulfur S 24

Formula: C2069H3278N574O628S24 Total number of atoms: 6573

Extinction coefficients:

Extinction coefficients are in units of M-1 cm-1, at 280 nm measured in water.

Ext. coefficient 52300 Abs 0.1% (=1 g/l) 1.112, assuming all pairs of Cys residues form cystines

Ext. coefficient 51800 Abs 0.1% (=1 g/l) 1.102, assuming all Cys residues are reduced

Estimated half-life:

The N-terminal of the sequence considered is M (Met).

The estimated half-life is:

                            30 hours (mammalian reticulocytes, in vitro).
                           >20 hours (yeast, in vivo).
                           >10 hours (Escherichia coli, in vivo).

Instability index:

The instability index (II) is computed to be 42.25 This classifies the protein as unstable.

Aliphatic index: 76.71

Grand average of hydropathicity (GRAVY): -0.368

Design Notes

Incorporated sequence overlap for Gibson assembly and no GC rich region or restriction site in sequence

Source

Chlamydomonas reinhardtii

References