SEC Form 3

FORM 3

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 INITIAL STATEMENT OF BENEFICIAL OWNERSHIP OF SECURITIES Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934 or Section 30(h) of the Investment Company Act of 1940

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1. Name and Address of Reporting Person* ARCH Venture Partners X, LLC (Last) (First) (Middle) 8755 WEST HIGGINS ROAD, SUITE 1025 (Street) CHICAGO IL 60631 (City) (State) (Zip)	2. Date of Event Requiring Statement (Month/Day/Year) 10/19/2022	3. Issuer Name and Ticker or Trading Symbol Prime Medicine, Inc. [ PRME ]
		4. Relationship of Reporting Person(s) to Issuer (Check all applicable) Director X 10% Owner Officer (give title below) Other (specify below)	5. If Amendment, Date of Original Filed (Month/Day/Year)
			6. Individual or Joint/Group Filing (Check Applicable Line) Form filed by One Reporting Person X Form filed by More than One Reporting Person

Table I - Non-Derivative Securities Beneficially Owned
1. Title of Security (Instr. 4)	2. Amount of Securities Beneficially Owned (Instr. 4)	3. Ownership Form: Direct (D) or Indirect (I) (Instr. 5)	4. Nature of Indirect Beneficial Ownership (Instr. 5)

Table II - Derivative Securities Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security (Instr. 4)	2. Date Exercisable and Expiration Date (Month/Day/Year)		3. Title and Amount of Securities Underlying Derivative Security (Instr. 4)		4. Conversion or Exercise Price of Derivative Security	5. Ownership Form: Direct (D) or Indirect (I) (Instr. 5)	6. Nature of Indirect Beneficial Ownership (Instr. 5)
	Date Exercisable	Expiration Date	Title	Amount or Number of Shares
Series A Convertible Preferred Stock	(1)	(1)	Common Stock	5,361,122	(1)	I	By ARCH Venture Fund X, L.P(2)(3)
Series A Convertible Preferred Stock	(1)	(1)	Common Stock	5,361,122	(1)	I	By ARCH Venture Fund X Overage, L.P.(2)(4)
Series B Convertible Preferred Stock	(1)	(1)	Common Stock	367,175	(1)	I	By ARCH Venture Fund X, L.P.(2)(3)
Series B Convertible Preferred Stock	(1)	(1)	Common Stock	367,175	(1)	I	By ARCH Venture Fund X Overage, L.P.(2)(4)

1. Name and Address of Reporting Person* ARCH Venture Partners X, LLC (Last) (First) (Middle) 8755 WEST HIGGINS ROAD, SUITE 1025 (Street) CHICAGO IL 60631 (City) (State) (Zip)

1. Name and Address of Reporting Person* ARCH Venture Partners X, L.P. (Last) (First) (Middle) 8755 WEST HIGGINS ROAD, SUITE 1025 (Street) CHICAGO IL 60631 (City) (State) (Zip)

1. Name and Address of Reporting Person* ARCH Venture Partners X Overage, L.P. (Last) (First) (Middle) 8755 WEST HIGGINS ROAD, SUITE 1025 (Street) CHICAGO IL 60631 (City) (State) (Zip)

1. Name and Address of Reporting Person* ARCH Venture Fund X, L.P. (Last) (First) (Middle) 8755 WEST HIGGINS ROAD, SUITE 1025 (Street) CHICAGO IL 60631 (City) (State) (Zip)

1. Name and Address of Reporting Person* ARCH Venture Fund X Overage, L.P. (Last) (First) (Middle) 8755 WEST HIGGINS ROAD, SUITE 1025 (Street) CHICAGO IL 60631 (City) (State) (Zip)

1. Name and Address of Reporting Person* CRANDELL KEITH (Last) (First) (Middle) 8755 WEST HIGGINS ROAD, SUITE 1025 (Street) CHICAGO IL 60631 (City) (State) (Zip)

1. Name and Address of Reporting Person* Burow Kristina (Last) (First) (Middle) 8755 WEST HIGGINS ROAD, SUITE 1025 (Street) CHICAGO IL 60631 (City) (State) (Zip)

1. Name and Address of Reporting Person* GILLIS STEVEN (Last) (First) (Middle) 8755 WEST HIGGINS ROAD, SUITE 1025 (Street) CHICAGO IL 60631 (City) (State) (Zip)

Explanation of Responses:

1. The shares of Series A Convertible Preferred Stock and Series B Convertible Preferred Stock (together, the "Preferred Stock") are convertible into Common Stock on a one-for-3.10880 basis at any time at the option of the holder, and will automatically convert into the number of shares shown in Column 3 immediately prior to the closing of the Issuer's initial public offering. The Preferred Stock has no expiration date.

2. ARCH Venture Partners X, LLC ("AVP X LLC") is the sole general partner of each of AVP X LP and AVP X Overage LP. Keith Crandell, Kristina Burow and Steven Gillis are members of the investment committee of AVP X LLC (the "AVP X Committee Members"). AVP X LP and AVP X Overage LP may be deemed to beneficially own the shares held by ARCH X and ARCH X Overage, respectively, AVP X LLC may be deemed to beneficially own the shares held by ARCH X and ARCH X Overage, and each of the AVP X Committee Members may be deemed to share the power to direct the disposition and vote of the shares held by ARCH X and ARCH X Overage. AVP X LP, AVP X Overage LP, AVP X LLC, and the AVP X Committee Members each disclaim beneficial ownership except to the extent of any pecuniary interest therein, and this report shall not be deemed an admission that such shares are beneficially owned by them for Section 16 or any other purpose.

3. Represents shares held directly by ARCH Venture Fund X, L.P. ("ARCH X"). ARCH Venture Partners X, L.P. ("AVP X LP") is the sole general partner of ARCH X.

4. Represents shares held directly by ARCH Venture Fund X Overage, L.P. ("ARCH X Overage"). ARCH Venture Partners X Overage, L.P. ("AVP X Overage LP") is the sole general partner of ARCH X Overage.

Remarks:

Exhibit 24 Power of Attorney. Exhibit 24.1 Power of Attorney

	/s/ ARCH Venture Fund X, L.P., By: ARCH Venture Partners X, L.P., its General Partner, By: ARCH Venture Partners X, LLC, its General Partner, By: Mark McDonnell, attorney-in-fact	10/19/2022
	/s/ ARCH Venture Fund X Overage, L.P., By: ARCH Venture Partners X Overage, L.P., its General Partner, By: ARCH Venture Partners X, LLC, its General Partner, By: Mark McDonnell, attorney-in-fact	10/19/2022
	/s/ ARCH Venture Partners X, L.P., By: ARCH Venture Partners X, LLC, its General Partner, By: Mark McDonnell, attorney-in-fact	10/19/2022
	/s/ ARCH Venture Partners X Overage, L.P., By: ARCH Venture Partners X, LLC, its General Partner, By: Mark McDonnell, attorney-in-fact	10/19/2022
	/s/ ARCH Venture Partners X, LLC, By: Mark McDonnell, attorney-in-fact	10/19/2022
	/s/ Keith Crandell, By: Mark McDonnell, attorney-in-fact	10/19/2022
	/s/ Kristina Burow, By: Mark McDonnell, attorney-in-fact	10/19/2022
	/s/ Steven Gillis, By: Mark McDonnell, attorney-in-fact	10/19/2022
	** Signature of Reporting Person	Date
Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
* If the form is filed by more than one reporting person, see Instruction 5 (b)(v).
** Intentional misstatements or omissions of facts constitute Federal Criminal Violations See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
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POWERS OF ATTORNEY
Exhibit 24


KNOW ALL MEN BY THESE PRESENTS, that each person whose signature appears below hereby constitutes and appoints Mark McDonnell his true and lawful attorney-in-fact, with full power of substitution, to sign any and all instruments, certificates and documents that may be necessary, desirable or appropriate to be executed on behalf of himself as an individual or in his capacity as a direct or indirect general partner, director, officer or manager of any partnership, corporation or limited liability company, pursuant to section 13 or 16 of the Securities Exchange Act of 1934, as amended (the "Exchange Act"), and any and all regulations promulgated thereunder, and to file the same, with all exhibits thereto, and any other documents in connection therewith, with the Securities and Exchange Commission, and with any other entity when and if such is mandated by the Exchange Act or by the Financial Industry Regulatory Authority, granting unto said attorney-in-fact full power and authority to do and perform each and every act and thing necessary, desirable or appropriate, fully to all intents and purposes as he might or could do in person, thereby ratifying and confirming all that said attorney-in-fact, or his substitutes, may lawfully do or cause to be done by virtue hereof.

IN WITNESS WHEREOF, this Power of Attorney has been signed as of the 29th day of January, 2021.

ARCH VENTURE FUND X, L.P.

By:      ARCH Venture Partners X, L.P.
its General Partner

By:    ARCH Venture Partners X, LLC.
its General Partner

By:        /s/ Keith Crandell
__________________________
Managing Director

ARCH VENTURE PARTNERS X, L.P.

By:    ARCH Venture Partners X, LLC
its General Partner

By:      /s/ Keith Crandell
__________________________
Managing Director

ARCH VENTURE PARTNERS X, LLC

By:   /s/ Keith Crandell
__________________________
Managing Director

/s/ Keith Crandell
___________________
Keith Crandell

/s/Robert Nelsen
___________________
Robert Nelsen

/s/Kristina Burow
___________________
Kristina Burow

/s/Steven Gillis
___________________
Steven Gillis



POWERS OF ATTORNEY
Exhibit 24.1


KNOW ALL MEN BY THESE PRESENTS, that each person whose signature appears below hereby constitutes and appoints Mark McDonnell his true and lawful attorney-in-fact, with full power of substitution, to sign any and all instruments, certificates and documents that may be necessary, desirable or appropriate to be executed on behalf of himself as an individual or in his capacity as a direct or indirect general partner, director, officer or manager of any partnership, corporation or limited liability company, pursuant to section 13 or 16 of the Securities Exchange Act of 1934, as amended (the "Exchange Act"), and any and all regulations promulgated thereunder, and to file the same, with all exhibits thereto, and any other documents in connection therewith, with the Securities and Exchange Commission, and with any other entity when and if such is mandated by the Exchange Act or by the Financial Industry Regulatory Authority, granting unto said attorney-in-fact full power and authority to do and perform each and every act and thing necessary, desirable or appropriate, fully to all intents and purposes as he might or could do in person, thereby ratifying and confirming all that said attorney-in-fact, or his substitutes, may lawfully do or cause to be done by virtue hereof.

IN WITNESS WHEREOF, this Power of Attorney has been signed as of the 29th day of January, 2021.

ARCH VENTURE FUND X OVERAGE, L.P.

By:      ARCH Venture Partners X Overage, L.P.
its General Partner

By:    ARCH Venture Partners X, LLC.
its General Partner

By:        /s/ Keith Crandell
__________________________
Managing Director

ARCH VENTURE PARTNERS X OVERAGE, L.P.

By:    ARCH Venture Partners X, LLC
its General Partner

By:      /s/ Keith Crandell
__________________________
Managing Director

ARCH VENTURE PARTNERS X, LLC

By:   /s/ Keith Crandell
__________________________
Managing Director

/s/ Keith Crandell
___________________
Keith Crandell

/s/Robert Nelsen
___________________
Robert Nelsen

/s/Kristina Burow
___________________
Kristina Burow

/s/Steven Gillis
___________________
Steven Gillis