Transcriptome and proteome analysis of Pinctada margaritifera calcifying mantle and shell: focus on biomineralization

Table 2 Protein identification in the shell matrix of P. margaritifera by a proteomic approach.

Protein	Matching peptides	Mascot score	Homolog protein	Accession no.	Identity	E-Value	Species
**Pmarg-Pif177**	26	1402	Pif177*	C7G0B5	72%	0.0	P. fucata
**Pmarg-N66**	16	759	N66* Nacrein*	Q9NL38 Q27908	81% 67%	0.0 1 e-123	P. maxima P. fucata
**Pmarg-PFMG10**	9	519	PFMG10	Q45TK0	56%	4 e-52	P. fucata
**Pmarg-Linkine**	6	278	Linkine	B5KFE5	100%	4 e-62	P. margaritifera
**Pmarg-Pearlin**	6	183	Perline* N14/Pearlin*	Q14WA6 Q9NL39	96% 92%	2 e-85 2 e-82	P. margaritifera P. maxima
**Pmarg-Shematrin-2**	4	340	Shematrin-8 Shematrin-2*	B5KFD0 Q1MW95	96% 68%	1 e-142 2 e-85	P. margaritifera P. fucata
**Pmarg-Pfty-1**	4	285	Pfty-1*	A1IHF0	59%	1 e-146	P. fucata
**Pmarg-Shematrin-5**	4	248	Shematrin-5	Q1MW92	54%	1 e-68	P. fucata
**Pmarg-MSI60**	3	181	MSI60*	O02402	78%	1 e-120	P. fucata
**Pmarg-MPN88**	3	126	MPN88	B7X6S0	47%	2 e-87	P. fucata
**Pmarg-KRMP-2**	3	121	KRMP-11 KRMP-2	A7X103 C4TPC8	88% 56%	1 e-30 7 e-14	P. margaritifera P. fucata
**Pmarg-Shematrin-1**	2	189	Shematrin-9 Shematrin-1*	B5KFD1 Q1MW96	98% 65%	4 e-99 8 e-62	P. margaritifera P. fucata
**Pmarg-Prismalin-14**	2	149	Prismalin-14*	Q6F4C6	68%	5 e-40	P. fucata

The trypsin-digest peptides were separated on nano-LC, prior to nanoESI-qQ-TOF analysis. The MS/MS spectra were used for searching against the pyrosequencing based EST mantle library with Mascot software. We only considered proteins that presented at least 2 matching peptides. Mascot protein scores are indicated together with the number of unique peptides that matched to the sequence. The homologies were determined by BlastP interrogations against UniProtKB/Swiss-Prot protein database (January 2010) using the UniProt on-line tool http://www.uniprot.org, setting parameters to default. We only show here the best matches for the contigs which protein sequences are the homologues of already known mollusk shell proteins. We notice that all matches are from Pinctada genus origin.
* indicates proteins which the occurrence in shell matrix was previously demonstrated by direct biochemical characterization.

ISSN: 1471-2164