aTYR PHARMA INC — Director's Dealing 2015

May 6, 2015

SEC Form 3 — Initial Statement of Beneficial Ownership

Issuer: aTYR PHARMA INC (LIFE)
CIK: 0001339970
Period of Report: 2015-05-06

Reporting Person: Domain Partners VIII, L.P. (10% Owner)
Reporting Person: BLAIR JAMES C (Director, 10% Owner)
Reporting Person: DOVEY BRIAN H (10% Owner)
Reporting Person: TREU JESSE I (10% Owner)
Reporting Person: SCHOEMAKER KATHLEEN K (10% Owner)
Reporting Person: VITULLO NICOLE (10% Owner)
Reporting Person: Halak Brian K (10% Owner)

Holdings (Derivative)

Security	Exercise Price	Expiration	Underlying	Shares	Ownership
Series C Preferred Stock	$		Common Stock (12143933)		Direct
Series D Preferred Stock	$		Common Stock (1506901)		Direct
Series E Preferred Stock	$		Common Stock (887073)		Direct

Footnotes

F1: All outstanding Preferred Stock will automatically convert into Common Stock immediately prior to the closing of the Issuer's initial public offering for no additional consideration. The Preferred Stock has no expiration date.

F2: These shares convert into Common Stock on a 1-for-7.95413 basis.

F3: These shares convert into Common Stock on a 1-for-9.6814 basis.

F4: The securities reported as directly beneficially owned by the designated Reporting Person may be deemed to be indirectly beneficially owned by each of the Reporting Owners listed below, each of whom is a managing member of One Palmer Square Associates VIII, LLC, the sole general partner of the designated Reporting Person. Pursuant to Instruction 5(b)(iv) of Form 3, each such individual has elected to report as indirectly beneficially owned the entire number of securities owned by the designated Reporting Person, however each of them disclaims beneficial ownership of any securities, and any proceeds thereof, that exceed his or her pecuniary interest therein and/or that are not actually distributed to him or her.

F5: As managing members of the sole general partner of DP VIII Associates, L.P., each Reporting Owner listed below may also be deemed to indirectly beneficially own the securities of the Issuer held by DP VIII Associates, L.P., as reported on a Form 3 for DP VIII Associates, L.P. filed on the same date as this Form 3.

F6: As managing members of Domain Associates, LLC, each Reporting Owner listed below may also be deemed to indirectly beneficially own the securities of the Issuer held by Domain Associates, LLC, as reported on a Form 3 for Domain Associates, LLC filed on the same date as this Form 3.